Introducing the revision of the Core BSS Examination Checking Procedures

A review of the core BSS Examination Checking Procedures (ECP) used for examining private boats; self-drive hire boats and many static let boats (e.g. B&B) and the interim revised ECP were adopted Autumn 2021.
Some final and further 2nd and 3rd stage enhancements will be published in early 2023 and then the Final version of the full ECPs and Appendices will be published shortly afterwards.

What Are The BSS Examination Procedures

The ECP sets out how the BSS Requirements are to be applied during BSS Examinations on privately owned and privately managed vessels and the relevant checks of the Hire Boat Requirements 2017. BSS Examiners use the ECP ‘manual’ alongside a checklist recording form, so new revised model BSS Checklists have also been created.

Please note: a reviewed and improved version of Part 10 of the Hire Boat Requirements will be published in February 2024.

The full Examination Checking Procedures for Non-Private Boats that was first published in 2002 is now in early review process in the BSS Committees. We will provide further information as the review progresses.

The Background to the revision process – How it happened

The interim review task began in 2019 and the aims were limited to:

  1. ensuring that the published ECP support the consistent application of the Checks by BSS Examiners; and,
  2. ensuring that BSS Examiner training can be effective to deliver an individual’s understanding of BSS Checking actions, Requirements and Applicabilities, whether the training is for existing Examiners or new-entrants.

The following factors were considered:

  1. a review of the historic comments, Check-by Check, made by Examiners on the BSS Database. Comments can indicate the level of understanding of the application of the Check; and,
  1. previous recorded discussions at BSS Technical Committee meetings; and,
  2. a review of the technical enquiries received into the BSS Office or collected during BSS Examiner Field Assessments or the new entrant training programme; and,
  3. comments made by Examiners arising during formal investigations alleging poor application of BSS Checks and procedures; and,
  4. information, generally from the marine industry that a specific Check may appear to contravene the way that boats are being built to comply with the Recreational Craft Directive, or that may appear to conflict with a supporting ISO standard; and more recently,
  5. in a need to explain the checks to new entrants, the development of the new BSS Examiner Training Programme learning material also influenced the final changes.

A considerable amount of detailed work by members of the BSS Technical Committee on accepting or refining the proposals drawn up by consultants to, and staff of the BSS.

At the next stage a sub-group of BSS Advisory Committee considered each developed proposal for change against the following terms of reference:

  • Does each proposed change make sense?
  • Does each proposed change support the aim of the project as set out above?
  • Can each proposed change be applied consistently in the field?
  • Are there any unforeseen consequences associated with each proposed change?

Impact of the changes

In broad terms, the impact of the changes can be described as follows:

  • several technical changes involving a slight relaxation of the BSS Requirements or the addition of further compliance options; and,
  • a large number of purely editorial changes, to help everyone’s understanding of the BSS Checks aiding greater consistency by BSS Examiners and increased compliance by boat owners and assisting the marine trade with understanding of the requirements.
    • Splitting of Checks
    • Merging of Checks
    • Swapping some Check numbers
    • Editing of check text, checking actions, requirements, and appendices
  • An expansion of supporting information in the BSS ECP Appendices from 18 to 78 pages covering processes, procedures and the BSS Checks
  • Deletion of a small number of checks
  • one additional feature as part of BSS Requirement affecting a very small number of trail-boats (Wilderness Boats) with LPG fridges - Check 8.2.2; owners are being contacted directly via the owners association
  • One other amendment concerns the clarification concerning allowable materials for fittings, joints and components used in gas piping installations. The two allowable materials are brass and stainless steel specifically. This means that ferrous/cast iron joints are not compliant, and this represents a re-iteration of the BSS requirements from the introduction of the BSS – see more details in the section below.

Naturally it is crucial that BSS Examiners need a keen understanding of the key changes of the revised Checks to help ensure the improved Checks are applied consistently. So all Examiners undertook an online course, introducing and explaining the revised ECP.

We predict that the improvements will have a very positive impact on the level of consistency of the application of the Checks by existing BSS Examiners, and will significantly improve the uptake of knowledge and understanding of trainees going through the New Examiner entry training programme.


While there have been several levels of checking and reviews to get the documents to this stage, with such a complicated process it is almost inevitable that some errors have crept in.

We welcome eagle-eyed readers feeding back with corrections we should make.


Improved consistency in the application of the published BSS Checks is one very important aim of the Interim Review.  However, we recognize that, leading from the proposed improvements in clarity and recent extensive training of Examiners, there is the potential for situations whereby an item may be newly discovered as non-compliant and so could require some adjustments or work to meet compliance and improve safety.

Similarly, the greater clarity in the Checking Procedures and the improved Examiner training may also address the relatively uncommon situation of any previous over-application the published BSS Requirements.

There are the two additional requirements set out below, but these are the only new requirements (technically these are reintroductions from before 2005) being brought forward in September 2021

These two changes only affect a relatively tiny number of boats with cast iron fitments on LPG systems and a few dozen Wilderness trail boats with gas fridges. (full details below)

Furthermore, September '21 edition of the checks also saw 20 further adjustments that resulted in either lesser requirements, or additional compliance options, which means the relevant checks may be slightly easier for some boats to comply with. There are tables below setting out the details.

However, around three-quarters of the 540 adjustments are editorial improvements or process amendments that will help everyone’s understanding and application of the BSS Checks, whether they are BSS Examiners, boat owners or members of the marine industry. We have provided some more detail in a 160-page document called – ‘Every Change Explained.’

Gas piping installations – BSS Check items 7.8.1R and 7.8.3R

Check 7.8.1R now refers to ‘pipes’ instead of ‘pipework’ - Are the LPG pipes made of a suitable material, adequately secured and free from damage? This is because we have a specific check for joints and fittings at 7.8.3R - Are all LPG pipe joints accessible for inspection and of the correct type?

Ferrous or cast iron pipes have always been non-compliant at this check and its predecessors since the inception of  the BSS Standards in 1997.

From 2005 to the end of September 2021, Check 7.8.3 used to say

  • All LPG pipe joints must be accessible for inspection.
  • All LPG pipe joints must be compression fittings on copper pipework or compression or screwed fittings on copper alloy or stainless steel pipework.

The check compliance requirements are now described in this way:

All LPG pipe joints must be accessible for inspection.

All LPG pipe joints used on copper or copper nickel alloy pipe must be:

  • brass compression joints; or,
  • brass threaded joints. [new allowance]

All LPG pipe joints used on stainless steel pipe must be:

  • stainless steel compression joints; or,
  • stainless steel threaded joints; or,
  • stainless steel welded joints. [new allowance]

This specifically limits the materials to the stated metals fitted to the relevant pipe type and introduces two new joint making options – one each for brass and stainless steel.

This aligns the check with the two harmonised standards used in CE & CA marked boats with gas systems installed. Both ISO 10239 and PD 5482-3 are specific in only allowing brass and stainless steel.

Both the ISO and the PD mentioned above exclude ferrous iron gas fittings as being unacceptable on boats for a number of risk-based reasons including:

  1. General corrosion of the ferrous metal (inside the fitting that may not be visible on the exterior of the fitting)
  2. Corrosion due to electrolytic (dissimilar metal) corrosion (within the fittings connections that may not be visible on the exterior of the fitting)
  3. Differential expansion and contraction (leading to pulled and leaking joints)

It also returns the BSS private boat requirement to where it was between the years 1997 to March 2005 which said: -

Visually check each joint is made as follows:

  • copper pipework - compression fittings;
  • stainless steel or copper alloy pipework – compression or screwed fittings.

While the 2021 version of 7.8.3R allows two additional joint making options, it in effect, disallows the use of ferrous iron or cast-iron joints and fittings, examples can be seen in the images below.


It is estimated that 100-200 boats, possibly less, would be affected by the clarification and disallowance of ferrous iron materials in LPG pipe joints.

It is likely that boats affected will be narrowboats built in the 1970s and 80s, or Dutch barges, and most commonly at the point that gas pipes exit the LPG cylinder locker such as seen in Figure 1.

LPG fridges on Wilderness trail boats – BSS Check 8.2.2R

The Check text now reads:

On petrol-engined vessels with a Wilderness Boats conversion of an Electrolux RM 212 refrigerator on board, are the burner enclosure and the flame arrestor at the ‘lazy tee’ in place, and is there suitable documentary evidence of recent servicing?

And the new element is for evidence of servicing:

There must be documentary evidence that the refrigerator has been serviced by Wilderness Boats or a Gas Safe registered engineer within the previous 12 months of the date of the Examination.

In considering this change, we have liaised with the designer and original producer of Wilderness Boats who continues to be involved with the Wilderness Boat Owners group.

The risk reason driving the change is that Wilderness Boat converted fridges are now 20-30 years old or even older, and some Wilderness Boat owners are reportedly removing the fridges as they are finding it difficult to have the appliance maintained correctly.

Given the high level of risk associated with a failure of the flame arresting enclosures around the burners and flue (two explosions in the past 12 months caused by LPG fridges on petrol powered boats indicates the risk level), so requiring these fridges to be serviced by a competent person within the preceding 12 months before BSS Examination is seen by the stakeholders, including the Wilderness boat Owners group, to be a modest and reasonable risk control measure.

As the Check now focuses on Wilderness Boat fridges, the Requirement can be more specific in terms of the flame arresting components.  This new approach will assist with Examiner application of the Check.

It is likely to apply to no more than 60-70 boats, possibly far fewer.

The introduction of relaxing the following BSS requirements supportable?

Please read the amendment explanations in the tables below which describe the nature of the proposed relaxations.

Table of lesser requirements


Check Text

Amendment Explanations


Petrol Tanks

Are petrol tank vent outlets fitted with a suitable proprietary flame arrester in good condition?

The requirement on diesel tanks is removed – revision aligns the BSS Requirement with the ISO standard, which does not require flame arrestors on diesel tank vents.


Petrol Tanks

Are petrol tank vent outlets fitted with a suitable proprietary flame arrester in good condition?

The mesh size specification is removed – this is because boats are, as manufactured, very likely to have arresters of ‘suitable proprietary manufacture’ and to continue with specified mesh size may cause a conflict.

The Check then becomes a check of condition of the proprietary flame arresters and their flame arresting gauze.


Gas stowage

Are all cylinders and cartridges stored in a position where any escaping LPG vapour will be directed safely overboard?

The minimum separation between cylinders in the open and ignition sources/openings into the interior of the vessel has reduced from 1m to 0.5m. This now aligns with ISO 10239 and PD 54823


Gas locker

Is the cylinder locker, up to the level of the top of the cylinder valves or other high-pressure components, free of any path for escaping LPG vapour to enter the interior of the vessel?

Withdrawn: ‘Door seals… … or pass the smoke pellet test’ [Deleted] - That part of the existing Check relating to smoke pellet testing is removed.

Examiners have never been trained to undertake the smoke pellet test, the test procedures are not set out anywhere.


Gas locker

Is the cylinder locker opening outside of any engine or battery space?

Revision: ‘electrical equipment space’ has been deleted because it was very difficult to define and because risk review did not support its continuation.


Gas Pipes

Are all LPG pipes running through petrol engine spaces jointless and adequately supported?

The original checking action included ‘Check for any LPG pipes running through petrol engine or electrical equipment spaces’ – has been amended to remove ‘electrical equipment space’, based on a risk assessment. Consequently, the BSS Requirements at Check 7.8.6 now only apply to petrol engine spaces.


Gas pipework

Are all LPG pipes running through petrol engine spaces jointless and adequately supported?

A revision for a gas line to be routed within a conduit or trunking, or supported by fixing clips which are no more than 300mm apart.

The part of the Requirement mandating the presence of a gas-proof conduit is removed and replaced with a Requirement for the gas pipe to be in a conduit or trunking or otherwise supported.

The new approach aligns the BSS Requirements with the specifications with ISO 10239.

Although the change does reduce slightly the specifications any added risk is considered to be insufficient not to align the BSS Requirements with the ISO.


Table of additional compliance options


Check Text

Amendment Explanations


Fuel filler

Does the internal diameter of the fuel filling point meet the specified requirements?

Revision aligns with the ISO and have the required i/d for filler pipes at 28.5mm and retain the BSS minimum i/d requirement for hoses at 31.5mm


Battery cables


Are battery cables of a sufficient current-carrying capacity?

New applicability – cables between batteries and battery isolators are permitted to have a cross-sectional area of less than 25mm² where it can be confirmed that the circuit only supplies low current domestic and/or navigation equipment (e.g. lighting, fridges, pumps, radios, etc)


Petrol stowage

Are all spare petrol containers and any spare portable petrol tank, stored to ensure that any leaking fuel or escaping vapour will not enter the interior of the vessel?

An applicability can take account of petrol stowage arrangements on CE Marked boats when assessed against BS EN ISO 11105 relevant to the boat build date


Gas locker

Are the sealing arrangements on LPG pipework exiting the cylinder locker of the correct type to ensure LPG-tightness and in good condition?

To better align with ISO 10239 - The revision adding ‘sealant’ as an acceptable form of sealing to the main bullet-pointed list of acceptable sealing arrangements.


Gas locker

Are the sealing arrangements on LPG pipework exiting the cylinder housing of the correct type to ensure LPG-tightness to the interior of the vessel?

To better align with ISO 10239 - The revision adding ‘sealant’ as an acceptable form of sealing to the main bullet-pointed list of acceptable sealing arrangements.


Gas locker

Is the cylinder locker opening outside of any engine or battery space?

Revision of a new applicability Examiner action - where a cylinder locker is found to open into an engine space the Examiner should contact the BSS Office to determine whether there is a known acceptable compliance option available for the model of boat.

This is because it is likely that some of the boats that fail this Check will be of a class of boat where there is a known compliance route already in place (such as with the Seamaster 23).

The new Examiner action therefore helps to ensure that boats are not failed unnecessary at this Check where relatively simple compliance options are available.


Gas pipe

Is the LPG pipe protected where it passes through metal bulkheads or decks?

The revision allows for equivalence - LPG pipes passing through metallic bulkheads or decks must be protected by the use of sleeves, grommets, cable glands, bulkhead fittings, or equivalent.


Gas pipe joints

Are all LPG pipe joints accessible for inspection and of the correct type?

New provision for ‘threaded’ brass joints on copper pipe included as acceptable. It is included in the relevant BS and ISO standards.


Gas pipe joints

Are all LPG pipe joints accessible for inspection and of the correct type?

New provision for welded joints on stainless steel pipe included as acceptable. It is included in the relevant BS and ISO standards.


Gas hose

Are all low pressure LPG hoses accessible for inspection, of the correct material and in good condition?

Revision in one Applicability to introduce EN 14800 which supersedes BS 669.

For the foreseeable future both standards are referenced.


Gas hose

Is all low pressure LPG hose protected against damage where it passes through bulkheads, decks or partitions?

This revision permits a further compliance option without promoting it as normal practice: - Applicability; it is acceptable for hose to be protected by sealant provided the sealant is in good condition and that it completely seals the area between the hose and the surrounding material, and provided the sealant does not noticeably move or dislodge when the hose is subject to light manual force.


Braided gas hose

Is all low pressure LPG hose protected against damage where it passes through bulkheads, decks or partitions?

This revision represents a clarification in regard to gas hose which itself is covered by a proprietary metal braiding does not require additional protection.


Gas appliance valves

Can all appliance supply hoses be isolated through individual appliance isolation valves?

New applicability - individual appliance isolation valves in the same LPG pipework spur as the appliance connected by hose, can be considered as meeting this Requirement.


Moving these amended BSS Checks forward

Reasonable arguments could be made as to whether the new text at 7.8.3R combined with the text change at 7.8.1R represents a clarification, a reintroduction, or an additional BSS Requirement

A public consultation was run on the changes to the requirements introduced by the review 29 May 2022.

Therefore in this interim and pending any consultation and its result, if an Examiner encounters gas piping joints that are ferrous iron or a gas fridge on a wilderness boat that has not been serviced, the examiner will be asked to contact the BSS Office for further advice.

The Consultation and its outcomes is published on this page [Link].


Further Information

All the current relevant to introduce the new documentation link to the revised ECPs is available below

The first seven pages of this document outline the review process adopted and explain the outcomes.

  • Public version of the ECP, Private Boat Checklist and ECP Appendices – see the link to the Private Boats Requirements webpage
  • Hire Boat Requirements Examination Record Form pad artwork incorporating the relevant core Checks
  • New Warning Notice form which has changed format from A5 landscape to A4 portrait for better visibility.

In December 2022 a second iteration of improvements and enhancements was agreed by the BSS Committees

The changes are textural, procedural and corrective, but not regulatory. They are listed in precise detail in the 'Every Change Explained Iterations 1 & 2 Jan 2023' document, but the overview is as follows.

The second iteration of improvements to the ECP (Interim) contains amendments based on three sources

  1. A few changes arose from responses to the public consultation (March – May 2022), on the first iteration interim ECP review;
  2. Most from both, BSS Examiner comments drawn from their experience of applying Edition 4 Version 0.2 of the ECP in the field since 28 September 2021; and,
  3. And, feedback from candidates at the BSS Examiner Training Courses that have run since late 2021.

The second iteration improvements comprise of:

  • 38 individual BSS Checks are affected.
  • 5 changes are made to the Glossary of Terms section of the ECP.
  • 10 changes simply recognise the post-Brexit change bringing in UKCA-marking alongside CE marking.
  • 1 new Check addresses an important aspect of a previous Check that was overlooked at the time that Check was deleted.
  • 16 changes ensure better consistency across the ECP, concerning terms used or text format.
  • 4 BSS Checks associated with the 16 changes referred to above, make reference to ‘essential’ or ‘supporting’ information within the Part 8 ECP Appendix. These additions align with many similar references to the Appendices throughout the ECP, and so the changes are consistent with the adopted approach. The relevant Part 8 Appendix text is provided as Doc D2, to help the review task. Note that the Appendix text has itself been recently developed by BSSTC to support the proposed improvements
  • 2 changes ensure further alignment of the BSS Requirements with the RCD harmonised standards.
  • 2 changes ensure that previously agreed BSS Technical Updates are implemented within appropriate Applicabilities.
  • 9 changes ensure better accuracy, including addressing typos.

A minimal third iteration of final improvements was introduced in September 2023 with all changes consolidated into one document