Again you miss a subtle point of procedure - it is not whether a HRA PTS would be 'acceptable' to individual Heritage Railways - its whether the HMRI / ORR and the insurance industry would consider it as robust as the current arrangements. Also comparisons with the Sentinel scheme should be done carefully, as the Sentinel scheme requires: The PTS holder has to:- Check the validity of their PTS compliance every time the enter non public railway infrastructure via an online portal accessed through a QR code on their photo ID card. If there is no internet signal than the card can be checked by calling a 24hr phone number and quoting the card holders unique ID - but such a procedure can only be done 3 times before the card is automatically suspended Have a pre-planned Safe System Of Work Pack detailing all risks and hazards or the stretch of line they are on. Have a COSS (Controller of Site Safety) appointed if there is more than a single person (If only one person is going lineside then they are known as an IWA (individual Working Alone) and are restricted as to what they can do. (In future it may become necessary to 'swipe out' so that fatigue etc can be monitored too). As such just because someone may have a NR PTS that in no way gives them permission to enter NR infrastructure whenever they feel like it, the company standards making it very clear you should only do so if your duties require it - and going lineside without a SWOPS pack it is a sackable offence anyway! Companies to:- Have certified training systems in place to ensure the PTS is of a sufficiently high standard. Recertify everyone at a maximum interval of every 2 years to ensure the necessary knowledge is retained by the individual. Reliable and quick methods available to inform Sentinel if a persons entitlement is suspended or if the card has been lost. Pay a significant membership fee to cover the costs of the scheme. Given all this, the question has to be asked - Is it really worth all the extra expense and hassle just so photographers can take pictures? - particularly as on most lines there are plenty of public vantage points (overbridges, foot crossings, etc) which are just as suitable.