Switzerland 1988: A very special route locking mechanism at Cham

Deutsche Version dieses Postings

Cham (pronounced K-aam) is a small Swiss station between Rotkreuz and Zug on the line from Zug to Lucerne. In 1988, I photographed the quite interesting interlocking frame. The track arrangement of the station, which can be seen in the following picture, is quite typcial: Three main tracks (2, 3, 4) and loading track 1 directly in front of the station building, a storage track and a shunting neck, and finally an industrial spur with a separate shunting signal. All signals were colour light signals. One each side, a single common signal for all four tracks was used as an starting signal, as was common in Switzerland on many smaller stations:

Track panel, Cham, 21.8.1988

The following image shows the whole frame. In the center, there are four signal levers, which—via electrical contacts—control the two home and two starting signals. Before them, one can see the wire roll of a fifth lever labelled "Von Anschlussgleis E" ("from spur E")—obviously, this lever reverses the shunting signal. Of more interest are the points levers: As in Grenchen Süd, they are reused route levers on the left and right of the signal levers. But the most interesting feature is the route locking: It is placed highly above the lever frame, in the brown box:

Interlocking frame, Cham, 21.8.1988

The next picture shows that the route levers are actually small cranks:

Route locking, Cham, 21.8.1988

Back side of interlocking frame, Cham, 21.8.1988

The inner workings of the frame can actually be checked out today, as the frame has survived at a museum: This link and that one point to images that show the following:

• the locking bed is now visible behind a plexiglass cover; 
• on the left side, the repurposed route levers for the points have once more be replaced with large levers; 
• and, above all, one can clearly see the connecting rods from the route locking box to the frame.

The website containing these images also shows that there is another similar frame which was located at Hinwil—but let me return to my own photos of Cham!

Here are the three points levers on the left side (the ones that have been retrofitted with mechanical levers), with corresponding locks on top. The downward rods go to a vertical locking bed:

Points levers, Cham, 21.8.1988

The next station's name, Rotkreuz, is written with old-fashioned "th" on these levers—near the route cranks, on the other hand, it is written with "t", so new labels may have been added there later:

Signal levers, Cham, 21.8.1988

Signal levers, Cham, 21.8.1988

Next to the mechanical frame, there stood an Integra frame with a single lever for a barrier. The main purpose of this frame was block working:

Electrical frame, Cham, 21.8.1988

Somewhere I took this photo of the controls for the overhead lines. The wall behind looks like it might be outside, on the platform. Unauthorized operation had been prevented with a metal rod, which would have to be unlocked with a square key and then moved a little bit to the side:

Switches for overhead lines, Cham, 21.8.1988

Unfortunately, the following image of the track side of the station is quite blurred—I just show it because of the small "tractor" or shunting engine which was still located at such small stations, for example to push a mail wagon on the back of a train. Here at Cham, it probably also shunted the spur mentioned above:

Station building, Cham, 21.8.1988

The image of the station building from the other side came out quite passable:

Station building, Cham, 21.8.1988