That would be the case if Barbers ceases to be the interchange point and it changes to Ayer (likely to become the case). Then it would be considered a direct interchange train and only require a Class III. If the interchange stays where it is at Barbers and the slip is only good till there, as soon as they start block swapping in Ayer with a new train symbol the cars will need to be retested. I am assuming they still swap blocks in Ayer correct? That is why we used to play games with the brake slips (MOPO, EDWA, etc) and have them terminate far beyond the away from home terminal so that they could swap blocks and keep the test. Trains like SEPO, 16R, etc do not require a Class I because they are direct interchange.
This is what was told to me on several occasions when FRA inspectors looked at our slips.
This is what was told to me on several occasions when FRA inspectors looked at our slips.