11 members met at the much changed Whitechapel station, where considerable Crossrail building work was in progress. Our group was led on a short walk through the streets to a plain unmarked door in a long, large plain wall! The door gave access to Whitechapel signal cabin with its 1951 Westinghouse 47 miniature lever frame and an illuminated diagram flanked by metal cased train describers (see pictures above). The approach of trains is indicated on the describers by a one or two letter code being shown. The destination codes seen during our visit were for Upminster (U), Barking (B), Barking sidings (Bs), Hammersmith (ML), Richmond (R), Wimbledon (W) and Ealing Broadway (E). The diagram shows the now reduced layout of basic double track with a crossover each end signalled to allow a reversing train to depart from its arrival platform. There are no 'rusty rail' workings. In practice, the crossovers are rarely used. As at other boxes like this previously visited, all the track circuits shown on the diagram are illuminated with diffuse white light except when occupied and, in one case, when there was an indication fault! The signal aspects are also displayed. See goo.gl/0APSKp for photos of Whitechapel.

Most levers in the middle of the frame are spare as the box also used to control St Mary's Jn (for the former west to south 'St Mary's Curve', CA Dec 2007, onto what was the East London Line, now part of London Overground), as well as lifted loops and sidings in the station. The signalman passed round several photographs and diagrams of the box's earlier equipment and track layout. On the wall is a clock in a fine wooden case and the signalman's only task for most of our visit was to enter the arrival and departure times of trains on paper on a clipboard. This was because there are two king levers, one for each direction, that when reversed allow the signalling to work automatically. He did however put a king lever back to normal and work the signals manually to prevent a train running early!

The next visit was to Barking, a 1960 installation that controls from Bromley-by-Bow to Dagenham East using a console with arrays of illuminated push switches. Every signal that is not an automatic signal has a controlling switch for each of its routes therefore most of the switches show red. A pre-selected route (i.e. chosen before the previous train has cleared) makes the buttons show orange. When the route is cleared and has been set up, they then change to green.

Trains are shown by an array of red lights on the diagram and the train describers for approaching trains use the same codes as Whitechapel but displayed as large letters on a VDU. Terminating trains described as 'Bs' (Barking Sidings), 6tph, unload in the station before going to siding 22 or 23 to reverse. When asked about using the other sidings instead, the signalman replied that he could but he would have to alter the sheet! Here again there is a clipboard and paper for times to be entered. The sheet lists the trains in scheduled order and specifies the siding number for the terminating trains. The signalman relies on this for turning the trains out of the bay and sidings in the correct order between through services from Upminster. The bay platform was used every 20 minutes and, though the rest of the route was set up, the bay exit signal No.7 was not cleared until departure time to prevent trains leaving early. The NR connection (not a signalled route) can only be used in an engineering possession.

Finally Upminster was visited where the building, shared with other railway functions, bears an external sign 'Underground Signal Box' although not underground!. It opened in 1958 and does not control the depot, so has a smaller push button console than Barking. During the visit all three LU platforms were in use and there were times when they were all occupied with trains being despatched punctually at five minute intervals. As at Barking, stations shown on the diagram have a small describer beneath showing the next westbound and eastbound platform departures, using the same destination codes as at Whitechapel.

Thanks to our member Rob Davidson and LU's Liz Massingham, who accompanied us and arranged the visits, and the three signallers who willingly answered all our questions. A stimulating worthwhile visit to this most interesting part of the Underground operation.