Public Liability Insurance arranged by the Association

The Association has taken Public Liability insurance, with a limit of indemnity of £5 million for any one incident, on behalf of members in the UK and Europe. The insurance provides cover for any event organised by a member of the Association that is attended by other members and invited guests, provided the track gauge is no more than 2½”. Depending on the circumstances, our Public Liability cover may also extend to certain events and exhibitions organised by members or local area groups and open to the public.

This page gives an overview of the cover provided. Further details of the cover and other files relating to insurance and locomotive maintenance can be found at the foot of this page.

Insurance and Boiler testing video

This video is an explanation and demonstration of the Insurance and Boiler testing scheme for members of the Association.

Further Information on Public Liability Insurance

The Treasurer, Ian Harper, is the director who is responsible for organising our Public Liability insurance. Our Technical director, Chris Trotman, is the best person to address questions about the insurance. Chris can be contacted on A copy of the current certificate of insurance is available at the foot of this page. A personalised copy of the certificate bearing the member’s name can be printed from our Members Only web site here. If you cannot access the site, please contact

Members and organisers of events or exhibitions should note that the Association’s insurance provides Public Liability insurance only. Members and event organisers who require additional cover (such as All Risks cover for models and home workshop cover) may wish to obtain a quotation from the Association’s insurance brokers:

Walker Midgley Insurance Brokers
Floor 5
Derwent House
150 Arundel Gate
Sheffield City Centre
S1 2FN
Contact: Martin Levers

Insurance Conditions Relating to Boilers and Gas Tanks

The guidelines used by the Association of 16mm Narrow Gauge Modellers, for the testing of steam boilers, are based on the Boiler Test Code 2018, Volumes 2 and 3. Volume 2 applies to small boilers under 3 bar.litres and Volume 3 applies to LPG tanks under 250ml. These codes apply to almost all boilers and gas tanks used in 16mm scale live steam locomotives.

The codes do not require repeat hydraulic testing of small boilers or gas tanks unless repairs or changes have been made. The test certificates provided by commercial manufacturers are fully acceptable as proof of successful completion of the initial hydraulic test. Volume 2 of the code requires repeat hydraulic testing of brass boilers every three years, albeit at 1.5 times planned working pressure, which ought to avoid the need to remove fittings. The reason for this is the risk of dezincification in brass boilers when exposed to water with any impurities. Volume 2 of the code does not require repeat testing of copper boilers. The majority of boilers fitted to 16mm scale live steam locomotives are copper boilers.

For example, a standard Roundhouse Argyll uses a copper boiler with a bar.litre capacity of 0.766, i.e. well inside the limit set by volume 2 of the code. The Roundhouse Q class gas tank as fitted to the twin-burner Darjeeling D class Garratt is 45ml capacity, again well inside the limit set by volume 3 of the code.

It is recommended that small boilers be fitted with a safety valve and a pressure gauge which has been marked by a red line to indicate the pressure at which the safety valve is set to lift. A steam test should be carried out and documented by the owner every 12 months in order to ensure the correct operation of the safety valve at the correct release pressure. This should be recorded on a copy of the Pressure Vessel Certificate 2018. The boiler and the pipework installation should also be checked at the same time.

The Association’s insurance policy provides cover for small boilers not exceeding 3 bar.litre and LPG tanks not exceeding 250ml whether or not a valid thorough examination certificate has been issued.  The Association nevertheless recommends that boilers and LPG tanks are in compliance with the guidelines of the code.

The 3 bar.litre limit is defined as the internal volume of the boiler (in litres) multiplied by the working pressure (in bar), where 1 bar = 14.5038 lb/in² and 1 litre = 1.76 pints.

It should also be noted that the 3 bar.litre is the guideline which is required by the Association’s insurance policy – other insurance policies may differ (especially for some exhibitions). If you are in any doubt, contact your local boiler tester via

If your boiler is above the 3 bar.litre limit then Volume 1 of the Boiler Test Code 2018 defines the testing regime for the boiler. Once initially certified, a repeat hydraulic test to one and one half times normal working pressure will be required and this will be valid for 4 years from the date of the test. A steam test is also a mandatory and required at intervals not exceeding 14 months.

It should be noted that a test certificate is invalid if the test equipment does not have a valid calibration record.

New professionally made boilers and gas tanks fitted to a locomotive or as part of a kit should be provided with a valid hydraulic test certificate. It should be noted that the boiler certificate generally only covers the hydraulic test and not a steam test. It is strongly recommended that a steam test is carried out if your model falls below the 3 bar.litre level. For “Homemade” boilers, volume 2 of the code requires that a hydraulic test is carried out at twice normal working pressure, followed by a system test with all boiler fittings at one and a half times times normal working pressure, followed by a steam test. An Association Boiler Inspector is able to perform this test – a list of Boiler Inspectors is provided at the foot of this page.

If you plan to construct a small boiler or a gas tank yourself then the Association recommends that you either contact us via, or your local boiler tester, to discuss the test requirements before you commence construction.

Insurance-related files

Locomotive Maintenance

You will also find useful resources (including our Locomotive Maintenance Chart, and guidance on carrying out the annual steam test) on the Loco Maintenance page.