For no especially good reason, let's have a dig in the National Archives.
The Whitechapel and Bow Railway was established at the turn of the 20th century to link the Metropolitan District Railway at Whitechapel with the London, Tilbury and Southend Railway at Bromley-by-Bow. The new underground connection was two miles long. It opened in 1902. Trains could now run through to East Ham and beyond. Three new stations were opened - Stepney Green, Mile End and Bow Road. Trains were initially hauled by steam. The line was electrified in 1905.
Along with electrification came a new set of signals on the line. In November 1906 Charles King, one of the engineers in the company's offices at St James' Park station, sent a typed letter to the Railway Department at the Board of Trade proposing how the new signals would be set out.
Herewith I send you (in duplicate) plan showing the proposed new Automatic Signals on the Whitechapel & Bow Railway, between Whitechapel and Bow Road. This will join the existing Mechanical Signalling at Bow Road at the East end; at the West end we are at present proceeding with the introduction of the Electro Pneumatic Signalling in Whitechapel Station, and shall shortly be in a position to submit plans and locking sheets for your approval.
The proposed design combined Automatic Signalling, Mechanical Signalling and Electro Pneumatic Signalling. The Underground has never been simple.
True to his word, Charles slipped (duplicate) plans into the envelope he sent to the Board of Trade. Each is gorgeously hand-drawn on card, as things always used to be, and show the tracks and signals from just outside Whitechapel to just past Bow Road. Platforms in yellow, signals mostly in green, and Bow Road's signal box in red.
(click to embiggen)
The only semi-automatic signals on this section of track were either side of Bow Road station, most likely because of the signal box. The remainder of the signals, all the way back to Whitechapel, were automatic.
Bow Road's signal box was needed because there were points here, indeed some trains used to reverse at Bow Road in those early days... which given the gradient just beyond the station can't have been ideal. 19 of the 29 levers on the mechanical frame in the signal box were not used. The points and the signal box are long gone.
What's great about this 1906 signalling diagram is the accuracy of the measurements. From the (automatic) signal at the head of Mile End's westbound platform it's precisely 844 feet and two inches to the next (semi-automatic) signal, and then 459 feet and 5 inches to the rear end of Bow Road's platform. To this day it's still one of the shortest gaps between stations on the suburban Underground, all 1303 feet and 7 inches of it. That's barely 397 metres in modern parlance.
Charles' accompanying letter continued.
I shall be glad to have your provisional sanction to bring these signals into operation, subject, of course, to any alterations which you may wish after inspection. Probably it would suit you to have these signals inspected at the same time as the new Whitechapel installation.
In due course the Board of Trade carried out their inspection.
They sent along a gentleman called Major Pringle, because that's how civil service employment worked in those days, and he duly filed a report.
I have today inspected the new works between Whitechapel and Bow stations on the Whitechapel & Bow Railway. Automatic signalling, on the electro-pneumatic system, has been brought into use, and the up and down lines have been divided into eight sections, as shown on the diagram attached. Repeating signals (with an orange light for danger) have been provided where necessary for sighting purposes.
The old signal boxes at Stepney Green and Mile End stations have been taken away...
Over the next few paragraphs the Major simply rephrases all the arrangements the engineer outlined in the first place - a useful parroting technique employed by generations of project managers since.
He concludes thus.
The arrangements are satisfactory, and I recommend the Board of Trade to approve the new works.
I have etc,
J.W. Pringle, Major
That valediction is short for "I have the honour to be, Sir, your obedient servant,", if you were wondering.
Electric District Railway trains continued to pass along the Whitechapel & Bow Railway using the new signalling. In 1907 this eastern spur merited four electric trains an hour off peak, running between East Ham and Ealing Broadway.
Meanwhile Charles's plans and the Major's reply were stamped and filed away in manilla folders, and ended up a century later in the National Archives in Kew, which is where I found them. That's Freedom of Information for you, if a little on the belated side.
Signalling in the Bow Road area is old and frail and in the process of being replaced, with occasionally mixed results (as previouslyreported). But there can't be any of this Edwardian infrastructure left between Whitechapel and Bow Road, surely, can there?