John Palmer wrote:My thinking is that the signalman asks the road whilst the excursion's locomotive is at the top end of the engine release, then, when it reaches the signal box, he hops aboard (with train staff, which he gives to the driver) (a) for a lift down to the ground frame (b) to authorise passing the starting signal at danger. The ground frame remains released throughout the run round. As soon as the engine sets back into the loop to couple onto its train the signalman clears Start from Loop with 4 Push and walks back to the box. If he stays at the ground frame to normalise it after the train has cleared the track circuit and only then walks back to the box, the train will have almost reached Highbridge East 'A' by the time the 'entering section' bell is given. Some support for this method of working can be found in a photo we have of an Armstrong standing ready to depart from the loop with its train. The ground frame can be seen in the background with the starting signal lever cleared but no signalman in sight - he's not waiting at the frame for the train to depart.
By way of a supplement to this topic, last Saturday night I was taking a look at some videos of the S&D which included footage of of an excursion using the loop in the early '60s. Motive power in question was Collet 0-6-0 3210, entrusted with a train comprising at least 8 coaches. The locomotive was seen at the east end of the loop, and of particular interest was the fact that the loop starting signal had
already been cleared as the engine set back past it onto its train for the return ECS working to Highbridge. The significance of this lies in the fact that, since the loop starter controls admission to the Burnham-Highbridge section, it is virtually inconceivable that this signal will have been cleared unless the train had already been offered to Highbridge East 'C' and accepted. In turn that means that, unless the ground frame controlling the loop starter was equipped with the block controls required to obtain that aceptance (which I think unlikely), it must have been obtained by a bell exchange between the signal boxes prior to the signalman operating the ground frame levers required to get the engine back into the loop. I think that lends some further support to my speculation above as to how despatch of trains from the loop was dealt with.