The whole subway station “Polytechnic Institute” in Kiev was reported to be closed soon only due to the malfunction of the escalator. It does not seem too reasonable, right? But why is repair of an escalator so difficult to do? Let us check this out.
The process may take one month or two. The tunnel escalator is a complex machine with a huge number of moving parts. There are more than 600 stairs and about ten thousand of bearings. Many parts are subjected to heavy wear: if the escalator works no-nstop, it will overcome twenty eight thosand of kilometers. Overhaul must be done every 170 thousand of kilometers. If it suddenly breaks the consequences can be rather bad.
During the overhaul it is almost fully disassembled in the strict order: stairs, pulling chains, guide rails, etc.
The orther day they finished the dismantling of the parts of the escalator under repair. Almost all of them were brought to shops of the escalator service: each detail must be disassembled, cleaned, examined and repaired, if necessary.
The most interesting place is hidden under the feet of passengers – the turbine hall.
The disassembled escalator looks like this now.
This is a turbine hall. To the left is escalator № 2, a bit righter is №1. № 3 is hidden at the opposite side of the room.
The first machine – to the right is the engine with a break unit, to the left, behide the lattice, an upper sprocket is rotating – the stairs are endlessly running over it.
On the other side is the gearbox casing, through which the torque is transmitted from the engine to the sprocket.
We can see inside the main construction and watch how the stairs, turned upside down, are moving.
Each escalator is equipped with a powerful drive motor, which should ensure the escalator to start lifting at the highest possible load.
The escalator is equipped with a automated brake at the input shaft. The brake, as well as the escalator itself, are filled with numerous sensors. Safety of passengers depends mainly on this mechanism. At the slightest risk the escalator should stop. That red button is for an emergency call.
The work of the escalator and its parameters are controlled from this box.
This is how the turbine hall of the first Kiev subway stations looked like.
Some old mechanisms are still in use.
Rails with turning tables have also been preserved. They are used to move cargoes over the turbine hall.
This is a spare drive motor.
But let us get back to the disassembled machine. Here only the reductor and the drum for braking have remained. In the center is the sprocket.
Parts of the safety enclosure lie nearby.
This is the reductor. Almost all parts of the brake are dismantled.
It’s the bearing of the main shaft.
The upper sprocket. The chain mounted over is pulling the stairs.
The force is transmitted from the engine to the main shaft through the gear, and the main shaft rotates the sprocket.
The operating corridor under the guard rail for the maintenance of the machines between the second and the third escalators.
Inside the disassembled escalator.
Handrail tensioning system is mounted in the upper part of the escalator.
The escalator is too long and its load may considerably vary so the extra system of handrail and stairs tensioning is necessary.
The tensioning chamber.
It’s the lower sprocket of the disassembled machine.
But how do more modern machines look like? This is “Pecherskaya” station which opened in 1997 and its turbine hall. The units are placed more reasonably: the drive motor is hidden under the upper sprocket, for example.
These are the upper sprocket of the forth machine and the open reductor (overhaul 2011).
The control station is also more compact.
Its’ the turbine hall of subway station “Syrets” (2004).
That little engine painted blue is also an auxiliary drive which is used during the repair and adjustment work to move the stairs at a speed not more than 4 cm / s.
The control station of “Syrets” has a modern electric filling.
And these are some assistants of the escalator service of “Syrets” subway station and they say goodbye to you!
Location: Kiev, Ukraine