As a recently-joined member, this is my first post. I regret that some of it will be a little negative. Please understand that I greatly admire what is being achieved by the members of the WW&F Railway Museum. My intention is to contribute, from afar, in what will be an ultimately positive manner.
Safety chains have been discussed in this thread. In the absence of a continuous automatic brake system, safety chains compensate by reducing the likelihood of and controlling the risks associated with train separation in cases of coupling failure. This is necessary so that unbraked cars will not run free, putting occupants and others in danger. A further advantage of keeping the train together is that brakemen will then have the best chance of bringing all of it to rest in a safe manner.
When continuous brakes have been fitted, it may be considered that safety chains will be no longer needed. In the event of train separation, both portions of the train will be brought to rest by the automatic action of the continuous brake.
Having studied the excellent and informative posted photographs of the trial WW&F continuous vacuum brake system, I have noted that end cocks have been included in the brake pipe of each vehicle. Some of these would be accessible by passengers. Accidental or deliberate closing one of these end cocks would remove brake system continuity in a train and a safety hazard would thus be introduced: the locomotive engineer could no longer control the automatic brake system throughout the train and the hazards associated with train separation would be introduced.
Historically, automatic vaccuum brake systems have never incorporated end cocks because they are unnecessary. Hose couplings self-seal onto the mating receptacles (termed “acorns”, because of their shape) that are provided at car ends. The vacuum holds everything together. A hose can be pulled from a receptacle (at the rear of a train) and replaced to prove continuity. Inside a caboose, a Conductor’s Emergency Cock is provided and connected to the brake pipe. By manipulation of that cock a train can be brought to a stand at any time.
End cocks are unsafe, as detailed above, and they are unnecessary. One of the beauties of the vacuum brake is its simplicity. That inherent safety is compromised by the introduction of unnecessary end cocks.
Another advantage of the vacuum brake is that it permits both graduated application and release of the brakes throughout a train. That makes for smooth train handling.
I do understand that the WW&F vacuum brake system is still experimental. I am sure that the proven and exacting approach of the WW&F shop forces will eventually produce a system that will be well worthy of those magnificent trains. I am sure that all realistic standards of safety will be met.
John B Scott
Melbourne
Australia
