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« on: December 09, 2018, 12:30:15 AM »
Joe, angle cocks are not needed and are not used on continuous automatic vacuum brake systems because the hose at each end of a train is placed on a receptacle and held there by the vacuum. In between, the hoses are coupled together between cars.
It is the presence of cocks in air brake systems, necessary to retain air pressure, that introduces the danger of inadvertently closed cocks that would interrupt the continuity of the air brake system throughout a train. Introducing unnecessary cocks in a continuous vacuum brake system would introduce the same danger. Without continuity a train may have insufficient braking power to prevent a runaway.
I believe that there is not a direct precedent for the continuous automatic brake that is envisaged for the WW&F, however there is an admirable expressed intention to make it as Eames-like as possible. That means we need to be open to all relevant and applicable Eames precedents, otherwise it will not be worth the bother. For loco 9 the issue is particularly tricky, given its great historical significance and the wonderful work that has been carried out to get it to where it is, now.
Personally, I think the British-style hose couplings and acorn receptacles are much better than the Eames flap-type couplings and, accordingly, it would be reasonable to upgrade according to the British model. Hypothetically, the original WW&F management could easily have followed that path, based on their experience. Even so, it might be rather intriguing, given our museum status, to try to see whether the Eames connectors could be made to work!
The introduction of cocks has no reasonable precedent and it would be unwise.