All of this is correct Steve, but the original question was about the Overlap
Block Sys, which came to be known as APB -- Absolute Permissive Block. CP also
had it on the Mattawamkeag and Moosehead Subs (maybe the McAdam Sub too) as
well as various Western Lines. Later, APB was simply bunched into ABS, though
the superior APB principles weren't ever eliminated anywhere; just the term,
and just for operating purposes. A lot of absolute signals were thus
introduced into ABS.
Also, it wasn't long after CPR acquired the line that became the Lyndonville
Sub that regular searchlight signals replaced the semaphores.
VRP
--- In cpsig@xxxxxxxxxxxxxxx, "midrly" <midrly@...> wrote:
I recall that this part of the CPR was former Boston and Maine Railroad. A
1931 article in Canadian Railway and Marine World on CPR signalling shows a
what appears to be a lower-quadrant two arm Union Switch and Signal Type B
semaphore signal. Like this one--
http://mysite.du.edu/~jcalvert/rail/jpegs/sptypeb.jpg
The article goes on to state that the CPR has "some 61 miles of the lower
quadrant type previously mentioned".
My "educated" guess is that this was the 63-mile Lyndonville Sub.
These lower quadrant semaphores are available from American Limited Models--
http://americanlimitedmodels.com/old/new_products.htm
Hope that this helps,
Steve Lucas.
