There are some semaphores remaining in the vicinity of Ryde St Johns Road station, under the command of the traditional mechanical signalbox there. Through the tunnels to Esplanade and over the water to Pier Head uses colour lights, as does the double track section to Smallbrook Junction. These are also under the control of the levers and mechanical locking at St Johns Road. A separate small switch panel, on the SB instrument shelf above the levers, controls the passing loop at Sandown, which has colour lights and is equipped with hydropneumatic 'train operated' points that, in the facing (diverge) direction, route trains automatically into the correct platform and are then 'run through' in the trailing direction to exit the station without damage occurring; the energy from the flanges of passing wheels pushing the switch rail open 'pumping up' the air reservoir in the device to hold the switch safely closed for the next facing movement. Illuminated Points indicators on the facing approach are used to inform the driver the switch rails are correctly positioned. I hope technical staff can lay their hands on a couple of additional examples of these units for the new Brading loop, as due to being entirely passive they simplify the control equipment requirements for a passing loop considerably. LU style mechanical trains stop devices were provided at key signals protecting junctions and single lines instead of TPWS in the early 2000s. The tripcocks that work with these on the former LU rolling stock were very easy to reinstate and will be equally trivial to retain on the new trains. The whole line is under control of one signaller based at Ryde so despite the headline age of the installation, the railway is actually fairly efficient in this OPEX respect. As with many simpler mechanical age installations, the box can effectively be kept going indefinitely and over the years much of the external and interior equipment will have been renewed routinely a number of times so the only 'original' features remaining may be the SB building itself and the main parts of the lever frame. This process could plausibly continue into the future as equipment needs to be replaced with incremental improvements incorporated as expedient. For example, axle counters might replace track circuits through the flood prone tunnels and on the sea spray vulnerable pier. Also signal heads or just the lamps inside could be replaced with low maintenance LED equivalents (where this has not already been carried out). All could be done without changing the underlying configuration of the interlocking hence limiting costs. The line is worked under track circuit block (TCB) regulations between Ryde Pier Head and Smallbrook Jn, then tokenless block (TB) to Sandown and the final spur to Shanklin is one train with no train staff (OTNS). The latter two systems do not have continuous train detection, so there is little intermediate signalling equipment in theses sections. Because the trains are continuously braked, tail light observation at the TB and OTNS clearance points is not required. Avoiding changes to the already very manpower efficient signalling will save a considerable amount of money. The new Brading loop will be very self contained and should ideally be built to the same standards as Sandown from a signalling point of view. It's worth noting train operated points can also be compatible with a 'Penryn-style' single split platform arrangement with one of the loop turnouts sited part way along the extended platform, if that is what is decided upon for Brading.
Sandown to Ryde via Bembridge is hardly a good example given that this runs once an hour: there are 4 buses an hour on the more direct route via Brading - and 2 trains per hour too, of course.
) it's not quite as outrageous as you think it is.
("Point of divergence", as the alternative-history geeks say, for my piece as linked-to: is September 1952.)