jwealleans wrote: ↑Tue Aug 04, 2020 10:50 am
I have seen at least one prototype photo showing the round bases but with no jumpers in place. It may have been withdrawn or under maintenance.
Could that be the photo of D120 E70213E In the Larkin book? It’s got the bases and plug stowage sockets but no cables. Caption states ex works from Stratford 1957. Definitely more like in works. There is no vac pipe or lamp brackets on the end.
On the following page is D120 E70240E at Eastleigh in 1958. Definitely in traffic and quite dirty. No jumper cables.
The next two photos of a D170 E70231E & D177 E70339E both have jumper cables.
I think it is the old adage of model from an actual photograph if absolute accuracy is required.
Back to the original title of this thread. The above has been very illuminating for the variants of the 4 wheel brake. However, it seems that whilst there are plenty of photos available of the Dia 170 and 177, photos of the dia 176 are a little more elusive - especially of the underframe.
I now have one of the Five79 kits, so it will have to be a case of educated guessing in some areas methinks - unless anyone wants to surprise me? Speak now or forever hold your peace...
One point that appears to have been overlooked so far is that using the Chivers Dia 120 underframe also requires the solebars to be repositioned closer together, to fit the standard arrangement of axleguard, axlebox and springing.
The Dia. 120 underframe is the same structurally as that used under the Dia. 86 General and 87 Milk Vans and was designed at Stratford, dual-braked and with through steam pipe, but the Pigeon Van has the addition of battery boxes and guard's brake standard linkage. It was originally intended to be 6-wheeled.
That underframe had the bulb angle solebars placed directly under the body sides for structural support, the additional width of more modern stock resulting in the axleguards being set further apart than would fit the standard axle, hence the need for the different axleboxes and rear springing.
For those interested in Diagrams 86, 87 and 120 there is a drawing of the underframe available from the NRM, reference SX25810. I have submitted an article describing the Dia. 86 and 87 Vans to the GER Society Journal which should be published with the official drawings for both body and underframe sometime in the next year - at this point I should perhaps add that the background described by Steve Banks on his website is pure conjecture; there was no NE influence at all in their development and design, they were pure GE but incorporating LNER standards for NPCS.