Cable trams operate using a moving cable located beneath the street, which the tram grips to propel itself forward. Here's a breakdown of how they function:
Cable Tram Mechanics
Cable trams, unlike traditional trams, don't have their own engine. Instead, they rely on a constantly moving cable located in a channel between the tracks.
- The Grip: The key component is the grip mechanism, located on the front "dummy" car. This mechanism extends down through a slot in the street and clamps onto the moving cable.
- Movement:
- To move: The driver clamps down on the grip, connecting the dummy car to the moving cable. This action pulls the entire tram, including the trailer car attached behind, forward.
- To stop: The driver releases the grip, disengaging the tram from the cable. The driver then applies the brakes to halt the vehicle.
- Tram Sets: Cable trams typically come in sets: an open-air "dummy" car at the front, housing the grip, and a closed "trailer" car for passengers behind it. The dummy is not designed to carry passengers, but to manage the grip mechanism.
Detailed Breakdown:
| Action | Mechanism | Effect |
|---|---|---|
| Start | Driver clamps grip onto moving cable. | Tram is pulled forward. |
| Stop | Driver releases grip; applies brakes. | Tram stops. |
| Movement | Cable moves in a continuous loop beneath street | Provides constant force |
Key Features of Cable Tram Operation:
- Constant Cable Motion: The cable is powered by a stationary engine located at a powerhouse, typically away from the street. This provides the continuous pulling force.
- Simplicity: The system is relatively simple mechanically, relying on the grip for engagement and brakes for stopping.
- Unique Configuration: The division of cars into the "dummy" and "trailer" is specific to cable tram systems.
Advantages:
- Effective in steep hills, where conventional trams struggle for traction.
- Reliable system.
Disadvantages:
- Requires a constant moving cable.
In summary, cable trams use a grip mechanism to connect to a constantly moving cable under the street to move. Releasing the grip and applying brakes stops the tram.
