1983 Stock Destination Blind
This destination blind, complete with its enclosure, passed to me through Haydn Brand, after the previous owner decided to sell it on. Thus, nothing is known of the blind's history between being removed from its redundant cab and its acquisition by me.
For saying that around twenty years had passed since this blind last saw service, it is in good condition, as is its enclosure painted Cornflower Blue. Unlike the other destination blinds in the Collection, the blind seen here may date from the stock's entry to service, given that the trains only saw about fourteen years' service, before being replaced in favour of the 1996 Stock. The text of these blinds is white with a black background. One difference that is noticeable immediately, when compared to the enclosures of older Underground stocks, is the absence of the hand crank mechanism used in changing the destination.
Four guide wheels would locate the enclosure into the ceiling of the Driving Motor cab.
Notice that there is a small aperture in the underside of the enclosure...
With the aperture slid back, the number 10 is visible through the inspection window. Rather than having whole destinations listed, the 1983 Stock destinations were depicted with unique number codes from 1 - 10.
The codes and their corresponding stations, along with their position on the blind are listed on a plate attached to the rear panel of the enclosure. To the right of the plate is the reason that this blind does not have a hand crank - these three buttons operate an internal motor that winds the blind mechanism clockwise or anti-clockwise, depending on the desired destination. This arrangement was unique to the 1983 Stock on the Underground, with subsequent stocks (including the 1986 Stock prototypes) featuring all-electronic destination displays.
No car number is provided on the rear panel, but the number '3702' is written in faint pencil beneath the 'No unauthorised person...' warning, which may have been the Driving Motor from which this enclosure was removed.
The manufacturer of the blind...sorry, 'Indicator', enclosure is situated at the other end of the rear panel. Evershed & Vignoles was taken over by Avo Ltd in the mid-1980s, and is known as Megger these days - a very familiar name in the world of electrical test equipment.
Opening the hinged rear panel reveals a far more technical-looking interior to this enclosure when compared to earlier products. The internal frame for supporting the blind mechanism is gone, with the roller spindles now being attached to the enclosure directly. An advantage of the electrically-operated blind mechanism is the considerable reduction in weight, but that is definitely the only positive point!
A nineteen pin connector is attached to the side of the enclosure (though only seven of the pins are fitted). Four of these are for the lamp, two are for the motor control and the last provides an earth bond to the metallic structure of the enclosure.
The seven salmon-coloured wires have coloured tags applied to their ends - this allows the individual wires to be traced throughout the enclosure, as the other ends of the wires contain matching tags.
The four lamp wires pass straight to the other end of the enclosure, where they terminate into an insulated block connecting them to the two lampholder wires.
The 20 W fluorescent lamp dates to September 1997.
With the lamp removed, more salmon wires connect the motor control buttons to the internal circuitry.
Removing a cover reveals the Printed Circuit Board that controls the motor operation. An MJ10003 Darlington transistor surrounded by a large heat sink takes up much of the space here.
The motor is sandwiched between the two rollers. A weighted frame attached to its rotor pushes the gear in the direction of one roller or the other, depending on the direction that the motor is turning at the time.