Accredited official statistics

Port freight statistics: notes and definitions

Published 19 July 2023

Introduction

Department for Transport (DfT) statistics on UK port traffic are published in 2 stages: (1) provisional quarterly releases, published 10 weeks after the end of the quarter. (2) more detailed final annual release published in summer of the following year.

All port freight statistics are published through the maritime and shipping series on the DfT statistics web page.

1. Purpose and usage

These statistics relate to freight traffic to and from ports in the United Kingdom. They provide an overview of patterns and trends in cargo handled by ports which inform the work of the DfT Maritime Directorate, as well as others with an interest such as industry stakeholder organisations, academics and researchers. The statistics were used to fulfil Eurostat reporting requirements under the Maritime Statistics Directive, which will continue to maintain a consistent time series and allow comparisons with other countries.

This document outlines the coverage of these statistics, including information on data sources and processing methodology as well as changes which have occurred to both methods and published outputs.

For more detailed information about the quality of the statistics, users and uses and responses to user feedback, please see the accompanying Port Freight statistics: Background Quality Report.

2. Definitions

2.1 Ports covered

These statistics relate to freight traffic to and from ports in the United Kingdom, unless otherwise stated, and do not cover ports in the Isle of Man or the Channel Islands.

Major and minor ports: from 2000, major ports are those with cargo volumes of at least 1 million tonnes annually. There are in some years a small number of ports with less tonnage who have either just fallen below the threshold, are showing a trend that they will exceed 1 million tonnes within a year, or have previously handled more than 1 million tonnes of cargo in a year. Prior to 2000 the threshold for ‘major’ ports was 2 million tonnes of cargo annually.

Details of the major and minor ports included are given in Annex A.

More detailed data are collected for major ports than for the remaining ‘minor’ ports. All tables starting PORT01 have been supplemented by estimated breakdowns of the minor port traffic.

2.2 Cargo classification

Cargo types: major port traffic is classified by cargo type, which is the means by which goods are loaded onto or of the vessel. Although for some cargo types there is further subdivision into broad commodities, the method of loading takes priority.

Weights: all weights stated are tonnes gross, including crates and other packaging. The tare weights of containers, road goods vehicles, trailers and other items of transport equipment (for example, the unloaded weight of the vehicle or equipment itself) are excluded.

Unitised goods: goods which are lifted on or of the vessel in large (20 foot or longer) shipping containers, or rolled on or off in one of a variety of self-propelled or towed units are said to be unitised cargoes. For these cargo types, the number of units as well as the weight of goods is recorded.

Main freight units: a subset of unitised goods are main freight units – this group consists of all containers and those roll-on, roll-off (Ro-Ro) units which are designed to carry freight (categories 51, 61 and 63 in the cargo categorisation flowchart). The purpose of the main freight unit classification is that it excludes those Ro-Ro units which are not freight carrying – such as passenger vehicles, trade vehicles, and other specialised vehicles and trailers.

Container traffic: for the purpose of maritime statistics, the classification of containers is based purely upon their length as shown in the table. TEU (twenty-foot equivalent units) is a standardised measure to allow for the different sizes of container boxes. Containers carried on board Ro-Ro vessels by shipborne port-to-port trailers are not included from 2000 onwards, although some operators incorrectly continued to include them until 2004.

Size	TEU
20ft	1
40ft	2
>20ft and <40ft	2.5
>40ft	2.25

2.3 Vessel information

Several of the data tables provide a breakdown by vessel characteristics.

In table PORT0604 nationality refers to the nationality of the parent owner of the carrying vessel. In table PORT0605, the flag denotes the country authorising the registry of the vessel. For more information on shipping fleets, see the latest Shipping Fleet Statistics tables.

Arrivals statistics - shown in tables PORT0601 and PORT0602 - include a vessel type breakdown (see Ship Arrivals section).

2.4 Geographical breakdown

UK port traffic is classified geographically according to where the goods were last loaded or next unloaded at the other end of the sea journey. All traffic is either domestic or international. Domestic traffic is either coastwise or one-port. International traffic is either short sea or deep sea, and short sea traffic may be further divided according to whether or not it is with another EU member state. A more detailed description of these terms is given in the table below.

Geographical classification of UK port traffic

Domestic/International	Traffic Type	Region	Note
Domestic	Coastwise	Coastwise	Traffic between ports in the United Kingdom (and with the Isle of Man and the Channel Islands). The totals of inwards and outwards coastwise traffic, however, do not match exactly. This is mainly because traffic between major and minor ports, or between major ports and ports in the Isle of Man and the Channel Islands, are not recorded at both ends (as is the case with coastwise traffic between major ports), but only at the major port end.
Domestic	One-port	One-port	Dredged sand, gravel and other similar cargo, landed at a port for commercial purposes; and traffic to and from UK offshore oil and gas installations (traffic with non-UK offshore oil and gas installations is recorded as foreign traffic). Formerly also included material shipped for dumping at sea, until this practice ceased.
International	Short sea	EU (as at 1 July 2013)	Traffic with Belgium, Bulgaria, Cyprus, Denmark (including Faroe Islands), Croatia, Estonia, Finland, France, Germany, Greece, Italy, Latvia, Lithuania, Malta, Netherlands, Poland, Portugal (including Madeira and Azores), Republic of Ireland, Romania, Spain (including the Canary Islands), Slovenia, Sweden.
International	Short sea	Other Europe and Mediterranean	Traffic with Albania, Algeria, Azerbaijan, Croatia, Egypt, Georgia, Gibraltar, Iceland, Israel, Lebanon, Libya, Monaco, Morocco, Norway, Russia, Syria, Tunisia, Turkey, Ukraine.
International	Deep sea	Rest of world	Traffic with all countries of Africa (excluding Mediterranean countries), America (both North and South America), Asia (excluding Mediterranean and Black Sea countries) and Australasia.

3. Data collection and processing

Information for shipping lines, their agents and ports to complete statistical returns on maritime freight traffic through UK ports. The legal powers to collect these data are by means of a statutory instrument (number 2330 of 1997) under section 2(2) of the European Communities Act 1972. The Maritime Statistics Directive is a piece of European Union legislation passed in December 1995 Council Directive 96/64/EC which requires Member States to supply to the Statistical Office of the European Communities (Eurostat) information relating to maritime traffic through its’ ports. The directive requires the government to make collection obligatory in the United Kingdom. The directive was ‘recast’ in 2009, bringing together the original directive and various subsequent amendments in one document. The legal powers in the UK are by means of a statutory instrument (number 2330 of 1997) under section 2(2) of the European Communities Act 1972.

Additionally, tables PORT0601 and PORT0602 provide information on vessels arriving at UK ports. These are compiled from a range of data sources (outlined in part B, below).

The port freight data tables also include information on domestic waterborne freight (DWF) in tables PORT0701 – PORT0705; this is based on re-analysis of information from the port freight system and additional information on inland waterway movements. Key differences are summarised in section C below, with further details in the separate notes and definitions document for DWF.

3.1 A: Port freight statistics

Data collection: data are collected from major ports and shipping lines and agents, on a quarterly basis, and from minor ports annually - in accordance with the Directive. Data providers can submit returns online using the Department’s ‘submit maritime statistics’ website or in flat file format. Full details - including collection forms, instructions and code lists - are available in the guidance for data providers.

From 2019, DfT collate the data, carry out initial validation checks, and also operate a helpdesk to identify and follow up non-respondents (prior to 2019, this process was managed by a separate collection agency). At the end of each quarter and year, additional checks are carried out, including the cross-comparison of port and agent records, and comparisons with previous time periods. Major anomalies are followed up with data providers. Further details of the collection and the quality assurance carried out, and strengths and limitations of the data, can be found in the separate background quality report (BQR).

Compilation methodology: published figures are based on annual totals by cargo type and direction provided by ports.

From 2000 all freight estimates shown in the tables which have a geographic element (for example, imports, exports, foreign, domestic traffic) have been estimated by grossing procedures based on information supplied by shipping lines and agents. Port figures are used as control totals, and figures from agents are grossed to port totals on annual basis to provide a breakdown by route and vessel information which is not collected from ports. Further details of this grossing are given in the BQR.

Before 2000, this information has been estimated by ports but only approximately in many cases. The post-2000 collection arrangements provide more reliable geographic information, for example, estimates of imports, exports, foreign, coastwise, one-port traffic and traffic on individual routes.

3.2 B: Ship arrivals statistics

The PORT0601 and PORT0602 data tables present statistics on the number of arrivals of commercial cargo and passenger ships at UK ports. These statistics are based largely on different sources of data to the statistics on cargo handled obtained through the port freight collection system described above.

The data are considered a reasonably accurate estimate of the number of commercial shipping movements at UK ports, but are not necessarily exact, and the coverage of certain vessel or traffic types may be variable at the margins. Consequently, these data are not classified as National Statistics.

The methods for compiling the statistics were substantially revised for 2010 data (and 2009 was also re-cast on the new basis, so that 2009 estimates are available on both bases for comparison), and again for 2018 data (with 2017 being shown for both old and new methods).

Arrivals statistics current methodology: the statistics are compiled on data from 3 sources:

1. Data from the Maritime and Coastguard Agency Consolidated European Reporting System (CERS), which is based on a mandatory reporting procedure for vessels arriving at UK ports. This includes information on around 100,000 vessel arrivals per year, although some regular services (mostly ferries) are exempt and it appears that some non-cargo vessels are not covered.

2. Data collected by DfT for monthly and annual sea passenger statistics. This source provides information on vessel arrivals for vessels which carry passengers, which includes the vast majority of those not captured by CERS.

3. Data collected as part of the port freight collection system as outlined above. Both ports and shipping agent returns capture information about cargo vessel voyages and this information is used where information is not available from one of the above 2 sources.

The overall estimates of arrivals are compiled by taking the best estimate from the above three sources for each vessel and port combination and aggregating them.

Comparison with previous approaches: the main change in the calculation method for 2018 was to replace data previously purchased from Lloyds List Intelligence (LLI) with data freely available from CERS. These sources differ in coverage, particularly for non-cargo vessels and minor ports - some of which are not well covered in CERS. A detailed comparison for the years for which both estimates are available suggests that these are not systematic; in some cases, CERS counts more vessels and in some cases less, but overall for most ports there was a good agreement between the different approaches.

Users should note that the arrival statistics are best estimates based on the data available, and subject to limitations. In comparing LLI and CERS data, it was noted that some movements within ports (for example, between different terminals within Milford Haven port) were being counted. Such movements have been excluded from the figures calculated under the new approach, wherever possible, which is one reason why the figures on the new basis are generally lower.

Vessels included: the ship types included in the arrivals statistics are shown in the table, these are unchanged from the previous approach. In table PORT0602, totals are shown for all cargo vessels - excluding passenger and other vessels - for consistency with previous approaches, and because the trends for these vessel types are likely to be more robust in general.

Ship type	Trading status	Vessel types included (based on Maritech world fleet data)
Tankers	Trading	Oil tanker, chemical tanker, liquid gas tanker, other tanker
Ro-ro vessels	Trading	Ro-ro passenger, Ro-Ro other cargo
Fully cellular container vessels	Trading	Container (fully cellular)
Other dry cargo vessels	Trading	Bulk carrier, refrigerated cargo, specialised carrier, general cargo
Passenger*	Trading	Passenger, cruise
Other vessels*	Non-trading	Offshore, dredging, bunkering tanker
Not included	Non-trading	Fishing, towing/pushing craft, other work vessels, non-seagoing ships, non-merchant ships,  non-ship structures, vessels of unknown or unrecorded type

‘Other vessels’ only includes those vessel types which may be carrying cargo which falls within the scope of the port freight collection system – for example, offshore industry supply vessels (including dual purpose vessels such as anchor handling tug/supply vessels), or dredgers. Work boats which are unlikely to be carrying cargoes falling with the scope of the port freight system are still excluded from the table – for example, tugs, offshore vessels other than supply ships, such as drilling vessels, pilot vessels, research ships, fishing boats and military vessels.

It is not possible to match the scope of the port freight system exactly using the vessel type classifications available, and the treatment of some vessels is ambiguous. For example, dredgers may be considered outside the scope of maritime statistics as being ‘work boats’ – however if they land cargo in a port, they are within scope of port freight statistics. Tugs are also excluded, but the cargo in any barges they are towing is again within the scope of port freight statistics.

The scope of the port freight system is theoretically limited to seagoing traffic – therefore traffic entirely within inland waters is excluded. The principal examples of inland waters traffic – Isle of Wight ferry services – are also excluded from the ship arrivals tables. It is possible that a small number of inland waters movements remain in the tables, but it is thought that the numbers involved will be relatively insignificant.

Strengths and weaknesses of the data: the data are thought to give a very good general indication of the overall level of significant seagoing commercial ship movements in the UK, but they are not necessarily completely precise.

The main limitations on the quality of the data are the accuracy with which major ports report traffic under the port freight system, and the completeness of the CERS data.

Combining 3 data sources and using different approaches for different ports and vessel types could introduce inconsistencies. However, checks suggest that for the majority of ports, the impact of this is likely to be minimal (though there are several ports where the estimation method is known to be less robust).

3.3 C: Domestic Waterborne Freight (DWF) statistics

As of the 2019 statistics (published in August 2020), figures for DWF are presented alongside the port freight statistics and included in the same statistical release. The publication of the 2020 DWF statistics were postponed to September 2021 following the identification of a data issue which affects the internal flow figures, which affects data from 2015 onwards. Data tables PORT0701 to PORT0705 contain DWF data.

DWF statistics are based largely on data collected through the port freight collection system, but processed differently and with some additional sources, which include:

1. Inclusion of data for inland waterway movements, which comes from a survey of barge operators, further information for inland movements (such as between Liverpool and Manchester) collected as part of the port freight system but not included in the port freight figures, and estimates for minor ports. It should be noted that when looking at internal waterways traffic, in 2019, more companies responded the Barge Survey and hence, internal waterways traffic may have seen an increase in their annual figures because of this.

2. Counting coastwise movements in only one direction; in the port freight statistics, coastwise domestic movements are reported twice - by the inwards and outwards ports. For DWF, one direction is counted (which is the one with the highest tonnage reported overall).

3. Calculation of figures for good moved, as well as good lifted (for example, tonnage).

There are separate notes and definitions for the DWF statistics which cover the methodology used in more detail.

4. Published tables and revisions

4.1 Publication arrangements: provisional and final statistics

Port freight statistics are published in 2 stages in order to put usable information in the public domain as early as possible:

1. Provisional quarterly results are published approximately 10 weeks after the end of the quarter to which they relate. These statistics are based on high level quarterly returns provided by major ports. Data are available for total weight of goods and number of units, inwards and outwards for each responding port. These figures may be subject to revision if subsequent checks at the year-end highlight anomalies. Typically, a very small number of ports do not provide data in time for publication, in which case figures are estimated. This usually applies to a small number of ports and has a minimal impact on the overall national trends shown.

2. Final detailed annual results are published about 7 months after the year end. These statistics are based on annual returns provided at the end of the year by each major port and minor port. A split into broad cargo type is available for each major port. At this stage a full reconciliation of port and shipping agent data will have been carried out, and grossing of the final data completed and checked. The detailed results are based on this grossed data. At this stage the full range of analyses, including those by route and vessel type are available.

Prior to the 2018 publication, statistics on DWF were published separately from the port freight statistics, however from 2018 onwards they have been included in one annual publication. Due to the identification of a data issue which affects the internal flow figures, affecting data years 2015 onwards, the publication of the 2020 DWF statistics were postponed to September 2021.

4.2 PORT data tables

Data tables published as part of the port freight series, including those containing data on ship arrivals and domestic waterborne freight, have the prefix PORT. Details of changes to published tables and how we work with users are given in the background quality report, but recent changes include:

1. For the 2017 statistics (published 2018), the format of the data tables was revised, introducing ‘filterable’ data tables to provide a greater range of information to users. A mapping between the old and new table numbers is available on the data tables page.

2. For the 2018 statistics (published in 2019), more minor changes were made, in particular the presentation of the arrivals tables (PORT0601 and PORT0602) was changed to be more in line with the other port freight tables.

3. For the 2019 statistics (published in 2020), more minor changes were made, in particular adding gross tonnage values to the arrivals table PORT0601.

Downloadable data file (PORT0499). This special file is designed to allow advanced users to filter for or download data for their own analyses. The data are disaggregated as far as is consistent with maintaining commercial confidentiality. Most of our published tables also have the raw data available within a ‘Data’ worksheet for use by interested users. PORT0499 contains data by number of tonnes as well as units. Note that not all unitised cargo types are capable of carrying cargo, therefore tonnage and units results should only be compared for those types of unit which can do so.

The tables contain data by year (from 2000), UK port, region of loading/unloading, country of loading/unloading, cargo category (at 2 different levels of detail) and direction of movement. Very small flows have been aggregated to world region totals to help maintain confidentiality.

Small flows. Small flows are defined by direction of travel and consist of unitised traffic weighing less than 500 tonnes and containing less than 200 units, or non-unitised traffic weighing less than 500 tonnes. In some of the data tables, these small flows are aggregated to preserve the commercial sensitivity of our data providers, as otherwise this data could identify specific shipping lines or agents.

4.3 Revisions

Where there are notable changes impacting on coverage of the published figures, these are noted in relevant changes. For example, Stranraer port closed in November 2011 and its operations were transferred to neighbouring Loch Ryan port.

Aside from the scheduled updating of the provisional figures noted above, revisions are occasionally made to correct inaccuracies. This includes minor corrections as follows:

1. Statistics during 2013 for freight handled by UK ports were revised to correct a small error found in the final statistics published on 27 August 2014. The original statistics included some underreporting due to a data supply issue identified through ongoing quality assurance processes.

2. Statistics during 2016 were revised to correct for a small error found in the tables and release published in September 2017.

3. During the production of the new published data tables in 2018, a series of minor errors were found on historical tables, mostly related to operations transferring between co-located minor ports and a reallocation of some cargo volumes (totals are not affected as a result). These have been indicated with an ‘r’ on the relevant table for that data point.

4. For the 2018 statistics, a minor revision was made to the vessel arrival statistics (tables PORT0601 and PORT0602) for Cairnryan port for years 2014 to 2016, to correct some double counting identified.

5. 2019 statistics were revised in the 2020 publication, published on 14 July 2021, due to volumes submitted for three ports - Goole, Grimsby and Immingham and Hull - being incorrectly inputted by the data provider. These revisions have resulted in there being an overall decrease in the volume of tonnage, and increase in the volume of units, between 2018 and 2019, which contradicted the original figures. TEU’s rose over the same period, but to a lesser extent after the revision. A summary of the revisions can be found in the below tables, as well as a cargo group breakdown of the changes for Grimsby and Immingham, and Hull, which were revised the most. Goole’s Other General Cargo traffic was the only group that was revised, down 5% from the original figure - 732 thousand tonnes – to 692 thousand tonnes.

Total change across for the 3 ports in 2019

	Tonnage	Units	TEU
Original	475,342,590	23,269,929	10,534,455
Revised	471,739,344	23,903,741	10,468,103
Change	-1%	3%	-1%

Total change across for the 3 ports in 2019

Port	Change	Tonnage	Units	TEU
Goole	Original	1,279,630	0	0
#Goole	Revised	1,242,431	0	0
Goole	Change	-3%	NA	NA
Grimsby and Immingham	Original	54,081,383	2,210,394	367,925
Grimsby and Immingham	Revised	51,245,356	2,121,245	322,182
Grimsby and Immingham	Change	-5%	-4%	12%
Hull	Original	9,927,329	570,356	344,883
Hull	Revised	9,197,309	1,293,317	324,274
Hull	Change	-7%	127%	-6%

Change across cargo groups for Grimsby and Immingham in 2019

Cargo Group	Change	Tonnage	Units	TEU
Dry Bulk	Original	14,313,307	0	0
Dry Bulk	Revised	13,358,373	0	0
Dry Bulk	Change	-7%	NA	NA
Liquid Bulk	Original	19,170,781	0	0
Liquid Bulk	Revised	18,141,138	0	0
Liquid Bulk	Change	-5%	NA	NA
Lo-Lo	Original	2,144,891	187,471	367,925
Lo-Lo	Revised	2,008,358	175,379	322,182
Lo-Lo	Change	-6%	-6%	-12%
Other General Cargo	Original	1,295,077	0	0
Other General Cargo	Revised	1,086,102	0	0
Other General Cargo	Change	-16%	NA	NA
Ro-Ro Non-self-propelled	Original	14,019,640	799,554	0
Ro-Ro Non-self-propelled	Revised	13,618,414	776,200	0
Ro-Ro Non-self-propelled	Change	-3%	-3%	NA
Ro-Ro Self-propelled	Original	3,137,685	1,223,369	0
Ro-Ro Self-propelled	Revised	3,032,971	1,169,666	0
Ro-Ro Self-propelled	Change	-3%	-4%	NA

Change across cargo groups for Hull in 2019

Cargo Group	Change	Tonnage	Units	TEU
Dry Bulk	Original	2,070,100	0	0
Dry Bulk	Revised	1,855,250	0	0
Dry Bulk	Change	-9%	NA	NA
Liquid Bulk	Original	1,631,097	0	0
Liquid Bulk	Revised	1,474,217	0	0
Liquid Bulk	Change	-10%	NA	NA
Lo-Lo	Original	2,168,057	190,374	344,883
Lo-Lo	Revised	2,034,474	179,000	324,274
Lo-Lo	Change	-6%	-6%	-6%
Other General Cargo	Original	1,626,298	0	0
Other General Cargo	Revised	1,530,420	0	0
Other General Cargo	Change	-6%	NA	NA
Ro-Ro Non-self-propelled	Original	1,554,719	119,313	0
Ro-Ro Non-self-propelled	Revised	1,323,329	106,391	0
Ro-Ro Non-self-propelled	Change	-15%	-11%	NA
Ro-Ro Self-propelled	Original	907,058	260,669	0
Ro-Ro Self-propelled	Revised	979,619	1,007,926	0
Ro-Ro Self-propelled	Change	8%	287%	NA

1. Figures for minor port Garston figures have been revised for 2020 and 2021, as data providers for this port were able to provide figures for these years in 2022. We had previously not received any data for Garston for years 2020 and 2021. Minor port and all port totals for these years may therefore be different to previously published data tables.

2. Figures for POR0605 have been revised for the year 2021 due to an error with the data which has now been corrected.

5. Strengths and weaknesses of these statistics

Port freight statistics undergo an extensive data validation exercise comparing data obtained from UK ports with data from shipping agents and operators (outlined in the background quality report). It is also possible to assess the quality of port freight statistics by comparing with other National Statistics, such as those produced by His Majesty’s Revenue and Customs (HMRC).

5.1 Port freight statistics: comparison with related data sources

HMRC’s Overseas Trade statistics record the movement of goods for trade purposes between the UK and non-EU countries. Detailed documentation of this system is available on the UK trade info website.

The 2 datasets can be compared to investigate whether there are similarities in reporting coverage and whether international port freight trends for imports and exports are consistent over time. Overall, the 2 data sources follow a similar trend in recent years, however, HMRC import and export statistics tend to be consistently smaller than those from DfT port freight statistics. It should be noted that HMRC reports the location of where the goods are cleared through customs, and this may be different from the port where the goods entered or exited the country.

5.2 Chart 1: UK major port non-EU international imports and exports from HMRC and DfT, 2010-2020

Even though HMRC data reports the cargo where it has cleared customs, as stated above, the location of where it was cleared may be different from the port of unload. To tackle specific geographical differences, it is interesting to observe the differences that might exist between countries in the United Kingdom, in order to improve the detail of the checks in the reporting of particular major ports. Chart 2 below shows a comparison for total freight imported and exported in the four UK countries.

5.3 Chart 2: UK major port non-EU international freight from HMRC and DfT by UK country, 2010-2020

Trends seem to be very similar for both data sources across the different countries, with constant differences for England and Northern Ireland as a consequence of over-reporting of dry bulk in port freight statistics, differences for Scotland driven by crude oil and oil products and caused by other liquid bulk cargo in the case of Wales. Nevertheless, as shown in the table below, correlation between series for each country are close to 1, with the exception of Scotland.

Country	England	Northern Ireland	Scotland	Wales
Correlation	0.89	0.82	0.45	0.85

Additionally, it is possible to look at this data source at the cargo category level, by comparing the tonnage of non-EU freight. This comparison is made by using a look up table that joins HMRC commodity codes, known as the Harmonised System of tariffs, to DfT cargo codes, as established by the European Commission Maritime Statistics Directive (95/64/EU).

Data from both sources for 2010 to 2020 for each subgroup were analysed with the findings discussed in detail below. Note that all comparisons are for non-EU UK major port traffic only.

5.4 Comparison of DfT port statistics and HMRC trade data, UK energy commodity traffic, 2020

Data Source	Liquefied Gas Imports	Liquefied Gas Exports	Crude Oil Imports	Crude Oil Exports	Oil Products Imports	Oil Products Exports	Dry Bulk Imports	Dry Bulk Exports
HMRC	14.4	0.4	36.4	11.4	12.6	4.0	15.2	6.6
Port Freight Statistics	13.6	0.5	33.1	9.1	12.0	4.8	31.2	5.4
Difference in Tonnes	-0.9	0.1	-3.3	-2.4	-0.6	0.8	16.0	-1.2
Difference in Percent	-6%	19%	-9%	-21%	-5%	20%	106%	-18%

5.5 Liquefied gas

For the liquefied gas cargo category, Chart 3 shows that the 2 data sources have very similar trends and the reported tonnages are extremely similar. There is a slight difference in the coverage of the two sources for imports, especially between 2017 and 2019, but the trends followed are almost identical, with 2020’s volumes being similar. For exports, although the values are very low, the differences are still minor.

5.6 Chart 3: UK major port non-EU imports and exports of liquefied gas, HMRC and DfT, 2010-2020

5.7 Crude oil

In the trends for crude oil imports, Chart 4 shows that the differences have greatly reduced in the last years, probably driven by better reporting of port freight statistics. For exports, correlation is near 0.93, which shows that both series have followed very similar trends across time. Again, in this case, the differences for exports could be driven by slightly poorer coverage of traffic from the port freight statistics.

5.8 Chart 4: UK major port non-EU imports and exports of crude oil, HMRC and DfT, 2010-2020

5.9 Oil products

Chart 5 shows that, in the trends for oil products imports, the differences have reduced in the last years, probably driven by better reporting of port freight statistics and better categorisation of cargo. Trends for both directions are very similar, although it should be highlighted that for imports, there have been several years where there have been noticeable differences between the two sources, such as 2017 and years prior to 2015. Nevertheless, absolute differences are very small for exports and almost negligible for imports in 2020.

5.10 Chart 5: UK major port Non-EU imports and exports of Oil Products, HMRC and DfT, 2010-2020

5.11 Dry bulk

Chart 6 shows that statistics for dry bulk follow similar trends for both directions, with correlations of 0.94 and 0.60 for imports and exports respectively. Differences for imports are mainly driven by poor categorisation of bulk agricultural goods in port freight statistics, which seems to be constant across time. When only considering the cargo categories ores and coal, the percentage difference of imports decreases from 106% to 25% in 2020.

5.12 Chart 6: UK major port Non-EU imports and exports of Dry Bulk, HMRC and DfT, 2010-2020

In conclusion, these comparisons show that these 2 National Statistics on freight goods products are broadly quite similar. Further investigation of possible over-reporting or wrong categorisation of dry bulk could lead to better reporting of port freight statistics.

5.13 Biomass estimates

Additionally, the biomass estimates provided on this publication are based on a commodity look up that filters HMRC Overseas Trade Statistics data for those goods that are used as biomass fuel (wood pellets, agricultural residues, seeds). With these cargo codes and an estimation of the importance of maritime freight in the biomass market, tonnage and value estimates have been generated for both EU and non-EU imports/exports.

6. Further information and lookups

6.1 Full list of current and previous ports included in port freight statistics

Includes some where freight operations have ceased.

View in Port and Domestic Waterborne Freight Table Information.

6.2 Chart 7: Ports, port groups and freight waterways

6.3 Cargo classification of port freight traffic

View the cargo categories for the EC Directive on statistical returns in respect of the carriage of goods and passengers by sea (2009/42/EC) in Port and Domestic Waterborne Freight Table Information

6.4 Cargo categorisation flowchart

The flowchart is provided to data suppliers to aid in the correct classification of cargo.

7. Annex A: Historical changes affecting these statistics

Port freight statistics have been collected in various forms for many years, with the current statistics including data back to the 1960’s (for example, table PORT0101). The current collection methodology for the core port freight statistics was established in 2000, following the introduction of the EU Maritime Statistics Directive. Although the published data series from before 2000 are considered to be largely comparable with the current system, the change in collection methodology resulted in some discontinuities in the data between 2000 and previous years.

7.1 Port freight statistics: previous data collection systems

Annual statistics on freight handled at Great British ports have been collected by DfT since 1980. Statistics for Northern Ireland ports were collected by the Department for Economic Development, Northern Ireland from 1988 to 1999, and have been collected by DfT within the UK system since 2000. Prior to this, similar statistics were collected by the National Ports Council from 1965. There were various relatively modest changes to the collection system during this period; these notes relate mainly to the data collection system from 1995 to 1999.

Prior to 2000 all freight information was collected from ports annually. There was no quarterly collection and no collection from shipping agents. A PS4 form was sent to major ports asking for detailed information on weight of traffic in and out, by cargo category and whether these were foreign, coastwise or one port cargoes. A detailed commodity analysis was also required for bulk traffic, and a broad commodity analysis for coastwise traffic. Separate information was required on unitised traffic, such as the number of units in and out by unitised cargo categories and by broad route. The current system includes more detail than previously on vessels and routes (in terms of the port of loading/unloading) used, and on unitised traffic by weight, but less commodity detail for non-unitised traffic.

The major ports covered by the PS4 were taken to be ports with at least 2 million tonnes of cargo a year. A few selected ports with smaller volumes were also included, which were required to provide only total weight of cargo, in and out, in a simplified form.

Main differences between the freight collection systems in 1995 to 1999 and from 2000

Difference	Freight collection system from 2000	Freight collection system in 1995-1990
Traffic Breakdown	More detail on unitised traffic by weight (for example, by size of container) but less commodity detail on non-unitised traffic. Change to definition of containers on Ro-Ro services (see table below for full comparison)	Less detail on unitised traffic by weight but more commodity detail on non-unitised traffic (see table below for full comparison)
Route and vessel information	Information on individual trips from shipping lines and agents, including port of load and unload, so geographic information should be more accurate. Also vessel details available, for example, LRN and flag. Summary data only from ports, on traffic in and out of ports, quarterly.	No information from shipping lines and agents and no vessel data. Detailed information annually from ports, but aggregated – no individual trips identified, so geographic information is likely to be less accurate.
Definition of major port	Major ports (52 in 2000) are defined as ports with annual cargo volumes of at least 1 million tonnes, plus a few selected ports with less tonnage. Otherwise ports are classified as minor ports.	Major ports (39 in 1999) defined as ports with annual cargo volumes of at least 2 million tonnes, plus a few selected ports with less tonnage. Otherwise ports classified as minor ports.

Comparison of cargo categories used in port statistics up to 1999 and from 2000

1) Weight of Unitised cargo

Cargo categories in use until 1999	Cargo categories in use from 2000
Containers on Lo-Lo or conventional services	All container categories
Containers on Ro-Ro services	If lifted on or off the vessel by crane then containers as above, if loaded using any type of roll-on roll-off trailer then rail wagons shipborne port to port trailers, and shipborne barges engaged in goods transport
Powered road goods vehicles and unaccompanied road goods trailers	Both Road goods vehicles with or without accompanying trailers and Unaccompanied road goods trailers and semi-trailers respectively
Rail wagons and barges carried on ships	Rail wagons, shipborne port-to-port trailers, and shipborne barges engaged in goods transport
Vehicles for import and export on Ro-Ro services	Import/Export motor vehicles
Other wheeled and Ro-Ro freight	Both Other mobile self-propelled units and Unaccompanied caravans and other road, agricultural and industrial vehicles Other mobile non-self-propelled units

2) Weight of non-unitised cargo

Cargo categories in use until 1999	Cargo	Cargo categories in use from 2000	Cargo
Liquid Bulks	Crude petroleum	Liquid Bulks	Crude oil
Liquid Bulks	Petroleum products and gas	Liquid Bulks	Oil products, Liquefied gas
Liquid Bulks	Animal and vegetable oils and fats, beverages, chemicals, chemical fertilisers, crude minerals, material shipped for dumping at sea, sugar and sugar preparations, and other liquid bulks	Liquid Bulks	Other liquid bulks
Dry Bulks	Ores and scrap	Dry Bulks	Ores and scrap
Dry Bulks	Coal, coke and briquettes	Dry Bulks	Coal
Dry Bulks	Foodstuffs and tobacco (including animal feeding stuff, dairy products and eggs, fruit and vegetables, meat and meat preparations, milled cereals and cereal preparations, sugar and sugar preparations and unmilled cereals), animal and vegetable oils and fats, and oil seeds and nuts	Dry Bulks	Agricultural products
Dry Bulks	Cement lime, chemicals, crude and manufactured fertilisers, crude minerals, iron and steel, material shipped for dumping at sea, non-ferrous metals, other non-metallic mineral manufactures, petroleum products and gas, sea dredged aggregates, wood lumber and cork, and other dry bulks	Dry Bulks	Other dry bulks
Semi-bulks	Unitised forest products	Other general cargo	Forestry Products
Semi-bulks	Other semi-bulk traffic (for example, iron and steel, and palletised cargo)	Other general cargo	Iron and Steel products
Conventional Traffic		Other general cargo	General Cargo and Containers <20ft
Non-Oil Traffic with UK offshore installations		Other general cargo	General Cargo and Containers <20ft

7.2 Port freight statistics: unitised traffic category changes from 2000

The following effects of an important change to the categorisation of ‘containers’ and ‘shipborne port-to-port trailers’ between 1999 and 2000 should be noted.

Containers can be lifted onto ships using conventional services at container ports (Lo-Lo) or they can be loaded onto Ro-Ro vessels – used principally for road goods vehicles, road goods trailers or passenger cars. The latter method often employs ‘port-to-port trailers’ used only within the port and which may return to the quay after loading or stay with the ship (either returning empty from the destination port or with another load).

Until 1999, Lo-Lo containers were included in ‘containers on Lo-Lo and conventional services’ whilst Ro-Ro containers were classified to ‘containers on Ro-Ro services’. From 2000 the category ‘containers on Ro-Ro services’ was discontinued and a new category introduced called ‘rail wagons, shipborne port-to-port trailers and barges’. Most containers previously recorded by respondents as Ro-Ro containers were subsequently recorded as ‘rail wagons, shipborne port-to-port trailers and barges’ but it is believed others were recorded as containers on Lo-Lo services. The effect of this definitional change can be seen in PORT0103.

It was evident by 2005 that some respondents operating at Ro-Ro ports were indeed incorrectly reporting containers transported on port-to-port trailers as Lo-Lo containers and had been doing so since the start of the new data system in 2000. This was corrected for 2005 when data providers were given further guidance.

Revised estimates for 2000 to 2004 for containers and shipborne trailers are provided in the table below.

The adjustment shown was calculated using updated information obtained from ports together with information from shipping lines and published sources. Comparative data is shown for 2005 to 2007. Note that the original figures for 2000 to 2004 have not been adjusted in the published tables.

It should be noted that in both the previous and current data collection systems containers carried by road goods vehicle or road goods trailer are correctly classified as ‘road goods vehicles’ or ‘unaccompanied trailers’ and not as containers.

Containers and shipborne trailers: 2000 to 2007 (thousand units)

	2000	2001	2002	2003	2004	2005	2006	2007
Containers	4,325	4,646	4,506	4,533	4,919	4,754	4,883	5,381
Shipborne trailers (original)	361	344	348	374	383	665	668	744
Adjustment to containers	-116	-157	-230	-265	-299	NA	NA	NA
…Of which London	32	-74	-173	-158	-166	NA	NA	NA
Adjustment to shipborne trailers etc	116	157	230	265	299	NA	NA	NA
…Of which London	-32	74	173	158	166	NA	NA	NA
Containers (adjusted)	4,209	4,309	4,276	4,268	4,620	4,754	4,883	5,381
Shipborne trailers (adjusted)	477	501	578	639	682	665	668	744

7.3 Ship arrivals statistics: previous methods

The approach used to produce the ship arrivals statistics has changed several times since they were first published. The current approach was established for the 2018 statistics. Details of previous approaches are given below.

Method until 2009: the scope of these estimates was cargo carrying trading vessels. The primary source used was commercially obtained vessel movement data from LLI. LLI maintain a global vessel movement database, based on a variety of sources, principally daily reports from an established network of Lloyd’s Agents and sub-agents, and increasingly also vessel tracking data from transponders which most vessels are now required to carry under maritime safety rules. LLI aim to cover “the deployment of all self-propelled sea going merchant vessels over 99 gross tons engaged in international seaborne trade”. The data obtained by DfT certainly includes domestic movements between UK ports, but it may be reasonable to suppose that data coverage could be less comprehensive in this category, particularly for small vessels, and/or those on very local or inshore routes.

The LLI data do not cover individual movements on frequent services (those with more than one call per day at the same port – mainly ferry services), so information on the number of these movements was compiled for DfT by a separate contractor and added to the total.

Method from 2009 to 2017: in 2012, new tables were released for 2009 and 2010, using a similar but revised method. These changes replaced a source of information on ‘frequent services’ no longer available, made better use of information already held, and expanded the scope of the table to cover non-cargo vessels. In table PORT0602, historical data are retained to allow comparisons to be made between the previous and revised approaches. The new method added about 5,000 vessel movements not identified by the old method (a 4% increase in the total) from the ‘fully cellular container’ to the ‘other general cargo’ category. This also applied to over 13,000 movements by vessel types not previously included, and over 1,000 arrivals of general cargo ships with container capacity, many of which were probably running container services.

LLI data continued to be an important basis of the method. However, it was merged with other information on ship movements obtained by DfT through the port freight collection system (all cargo or passenger carrying movements at major ports) and its sea passenger survey (movements on regular seagoing ferry services). The three data sources are merged at the level of individual vessels calling at each port. The maximum number of calls from any of the three sources is taken as the final estimate. In the small proportion of cases where it is not possible to match vessels to other sources, these movements are also included in the total for the relevant port.

A further difference in the method used from 2009 is that in nearly all cases vessel type is based on IHS Global world feet data. Under the old method (figures to 2009) vessel type information came largely from LLI, except for those vessels on frequent services which did not appear in the LLI data set. This change was made because data were being merged from more data sets. In general, LLI and IHS Global sources agree on vessel type, but there are some cases where they differ – since some vessels can be employed in a variety of roles. Generally, this does not make a significant difference to the overall results, but one relatively major change is for smaller container ships. The old method classified LLI’s ‘General cargo with container capacity’ category as container vessels. In general, the vessels in question were employed on container services. However, they were not ‘fully cellular’ – that their container cell guides were not fixed, allowing the vessels to be configured for other cargoes. Therefore, these vessels appear under the ‘other general cargo’ category in the new tables. Consideration was given to whether vessels identified by IHS Global as having container capacity should be included under the ‘container’ category, but this would have led to much larger discontinuities in the opposite direction, with the probability that many vessels operating as general cargo ships would be misclassified as container ships.

Between 2009 and 2010, LLI increased the coverage of their data. The impact of this on the DfT tables results is probably significantly reduced because many of the additional movements recorded by LLI would already have been captured in one of the other sources used in the DfT statistics.

8. Contact details

Maritime and shipping statistics

Email maritime.stats@dft.gov.uk

Media enquiries 0300 7777 878

To hear more about DfT statistical publications as they are released, follow us on Twitter at DfTstats.