A Stock Destination Blind
Thanks to Haydn Brand for supplying this fantastic piece of Underground history. This destination blind (complete with its original housing) was removed from the cab of A60 car 5086 upon the decommissioning of its unit (5086-6086-6087-5087) in September 2011. The blind and its housing are in good condition for their age, with the only remedial work being a comprehensive surface cleaning, and replacement of the lighting unit.
I had already removed the blind mechanism from the box by the time that these pictures were taken. The front "window" of the enclosure does not contain any sort of glazing panel; instead, the box would be positioned up against the glass panel located immediately above the cab's 'M' door. Adhesive foam strips have been applied around the perimeter of the front section; presumably, in an attempt to keep the inside of the glass, and the blind itself, clean. These strips are now loose, broken or missing completely and will be removed. The lighting system comprises a single 600 mm 20 W fluorescent lamp, with a separate wire connecting each of the lamp's four terminations. The lamp control gear would have been installed remotely. The enclosure measures 2 ft 411⁄32 inches (720 mm) × 815⁄16 inches (227 mm) × 563⁄64 inches (152 mm).
The rear of the box provides details of the destinations that are included on the blind; these are arranged in the order that they appear on the roll. The car number is handwritten in the centre. To the left of the "No smoking" sticker are the remains of a further two stickers that appear to have been added unofficially by a member of staff at some point. Access to the blind mechanism is gained by releasing the two slotted screws on the lower side of the box and then raising the panel upwards.
Close-up of the list of possible destinations - notice that the "Baker St" and "Aldgate" destinations appear twice.
Car 5086 was an A-end Driving Motor. Its D-end equivalent, 5087, was never converted for One Person Operation and would therefore always have formed a "middle" cab. This setup would also prohibit the unit from operating in passenger service as a standalone unit - it would have to be coupled to another unit before being permitted into service.
The top of the box was in a particularly grubby condition. Two mounting brackets can be seen that would have attached the box to the car ceiling. Very faint traces of the deep red paint applied to the A Stock interiors when the trains were new can still be seen on the brackets - these will be retained. The cut wiring to the light can be seen leaving the box.
A small window is provided that allows the destination to be aligned correctly in the main outer-facing window - a three-letter station identifying code is printed on the side of the blind roll, and once this is visible within the small window, the destination is displayed correctly. A label to the right of this window informs us that the box was last overhauled at R.E.W. [The Railway Engineering Worksop], Acton, in September 1997. (I know this date cannot be seen here, but trust me; that's what it says!) Above this is where the crank that operates the blind mechanism fits - a small panel secures the crank once the mechanism is in place.
As the light fitting is attached to the inside of the hinged rear panel, it swings out of the way when the panel is opened, allowing easy access to the blind mechanism (when fitted!). The lugs visible inside the box, on the "top", are used to secure the mechanism to the box. Two further lugs are positioned directly opposite, on the lower section. The four incoming single-core cables for the light all terminate into an insulated central connector, to which the lampholder connections then attach. Although 20 W fluorescent lamps run at around 60 volts, it is unlikely that this means of connection would be employed today, owing to live terminals being exposed.
The roller mechanism is built around a basic chassis, with the crank being attached to a rod incorporating two gear wheels. An ingenious clutch system engages and disengages two lower gears depending on the direction that the crank is rotated. The two spindles that the blind collects around (removed in this picture) fit into the assembly by means of a spring-loaded panel on the left-hand side. Various cylindrical rods then keep the blind in shape. The bolts for the lugs mentioned above can be seen in this view.
Close-up of the crank. The pointed conical object down and to the left is one of the supports for the guide rods.
A considerable amount of copper grease had been applied to the mechanism prior to the acquisition of the blind. The previously mentioned clutch system can just about be seen here - it is a marvel of engineering, and although probably nowadays considered old-fashioned on account of the popularity of LED destination indicators, I just love the fact that someone has had to devise this mechanism, and that it still works all these years later.
We now look at the two spindles and support rods. The blind attaches to the spindles by means of a thin rod that fits through a folded section at the very start of the blind. This rod then slides into the channel that is cut into the spindle (visible in the picture) and is then secured by the end cap being inserted into the spindle.
My first task was to remove the wiring in preparation for the much-needed cleaning of the box. The old wiring, and all of its associated cable clamps, were removed.
Meanwhile, the surface dust was removed from the mechanism skeleton, and the blind reattached.
The guide rollers ensure that the section of the blind that will be visible remains taut at all times.
This view demonstrates the placement of the spindles, and how they attach to the mechanism.
Cleaning the box proved more of a challenge than I was expecting - a lot of the dirt was ingrained and required considerable elbow grease to be removed. The unsightly foam strips were removed from the front of the box, though the material used to make them adhere to the surface had reacted with the paint, leaving a faint ghost image around the perimeter. In time, I may repaint the box in order to remove the marks completely.
The remnants of the "unofficial" stickers were removed using a chemical that was originally found to displace water after the 40th attempt at producing a formula...or WD-40, as it is more frequently known!
The top of the box was now far more presentable.
The underside was so clean that the small indicator window was now useful again!
As part of this work, the "terry" clips fitted as a means of supporting the lamp were removed, as they would not be required for the replacement light fitting. The copper rivets that secured them to the lid were drilled out; these holes will be re-used for attaching the supports for the new light.
The blind assembly was then temporarily re-installed; as can be seen, it is a tight fit!
Turning the box over, notice that the window is slightly off-centred. This is to allow space for the mechanism and inspection window to be accommodated.
Proof that the inspection window works! The window appears wet here as the box was still drying off.
A new LED light fitting was installed. Where possible, the original cable clamps were re-used.
A convenient space below the larger of my two A Stock luggage racks served as a perfect location for the blind to be installed (yes, that is an A Stock reverser key on the left, and a Guard's key on the right). Two heavy-duty shelving brackets were installed as a means of supporting it. In order to prevent the momentum of the crank from causing the box to slide around on the brackets, a strip of Velcro was applied to the horizontal sections, with the secondary piece then being applied to the underside of the box. The mechanism was re-greased, and a piece of acrylic installed between the blind and the front of the box. I understand that the red aspects located at both ends of the blind were intended to serve as emergency tail lights, should the need have arisen. This method probably superseded the hanging of a lamp displaying a red aspect on (what would be) the rear cab of the train.
The destinations of "Chalfont" and "Chesham" are located together on the blind; this would allow for quick changing of the destination for trains that operated the former shuttle service between the two stations.
Of course, though, the place that puts the "A" in "A Stock" is a certain town in Buckinghamshire...
Video footage of the various destinations being displayed on the blind:
The table below lists the destinations, along with their three-letter identifier code:
|SORRY NOT IN SERVICE||SOR|
|FAST BAKER ST.||FBA|
|NEW CROSS GATE||NCG|