Northern line 1959 Stock 'bobble hanger'
The 1959 Stock was the last Tube stock to be running in passenger service with this type of hanger being employed, although the sub-surface D78 Stock trains used on the District line had similar (but longer, due to the higher ceilings) hangers until they were refurbished. In order to prevent the spring from being pushed or pulled too far, a steel cable is incorporated inside the coils and is secured at either end of the hanger. When in use the top of the hanger would have emerged through the top of the fixing bracket and be prevented from removal by a mechanism in the ceiling of the car. Notice the 1990s car diagram in the background.