Switzerland 1988: Mechanical frame and semaphores at St.Blaise

Deutsche Version dieses Postings

This text contains, in italics, comments by Hanspeter Thöni which answer a host of my questions and shed more light on many issues.

On the previous day, we had been travelling through St.Blaise, where old semaphores had caught my eye. On the next day, we therefore returned to this small station near Neuchâtel. During our trip along the Jura foot line, I could take a few photos of signals from the cab of the control car. The first picture shows at its edge two distant signals, one "announcing clear" ("Fahrbegriff 1^*"), the other "caution" ("Warnung"):

Distant signals, where?, 17.8.1988

To the left of the oncoming Re 4/4 11243, one can see (unfortunately, I do not remember the station name):

• "Clear" ("Fahrbegriff 1"),
• then "announcing 90km/h" ("Fahrbegriff 5^*")

Home signals, where?, 17.8.1988

Leaving the same station, one can see (click shows, as always, a larger version of the image)

• "Execution 90km/h" ("Fahrbegriff 5"),
• then "announcing clear" ("Fahrbegriff 1^*"),
• and finally a departure signal (similar to the British "right away" indication).
• Near the ground, there is a dwarf signal showing "clear".
• To the left of the next track, one can see a closed stop signal with an attached distant signal showing "caution".

Starting signals, where?, 17.8.1988

I also cannot locate the following combination signal with eight lamps, showing "clear":

Combination signal, 17.8.1988

This Ae4/7 came on too quickly:

Ae4/7, ?, 17.8.1988

In a station somewhere before St.Blaise, I pressed on the trigger once:

Mechanical frame, where?, 17.8.1988

But this is already the home signal of St.Blaise:

Home signal D^1/2, distant starting signal ("Durchfahrsignal") D^d, St.Blaise CFF, 17.8.1988

Here are two track plans of St.Blaise. The first one is from the original track panel and shows signals cleared for a through train towards Neuchâtel:

Here is my schematic diagram. The points and tracks shown as dashed lines had been removed some time earlier, but they are needed to explain why there are two-arm semaphores at either end of the station. The removals have essentially left over a torso of a station which cannot be used for passing trains any longer (click opens a readable PDF file):

Here is my first picture of the frame:

Signal box, St.Blaise CFF, 17.8.1988

The next one shows the complete frame. At the back, there are the block instruments, with the route levers below. The frame contains the red signal levers and blue points levers. Astonishingly, the lever for points 1/2^b is reversed: Some shunting movement must have taken place at this station exactly when my visit started! (I remember that the signalman and I could not exchange one word, because I cannot speak French, whereas he could not talk in German). At the back of the lever, one can see the toothed rack pulled up by the lever, which transfers its movement to the points via the points rodding:

Block instruments and interlocking frame, St.Blaise CFF, 17.8.1988

It is interesting how many electrical "things" accumulate in a signal box over time. I have cut out the left upper part of the previous image here—one can see a host of switch boxes with and without fuses, switches, cables and ducts in between (an old wooden one, more modern plastic ones), and, on the right, a bell for an unknown purpose:

Electrical, St.Blaise CFF, 17.8.1988

Here is the track panel with signal and track occupation indicators, with a train is running Neuchâtel. The center is, unfortunately, hard to see due to my flash, but one can see the masked lines of the removed tracks:

Track panel, St.Blaise CFF, 17.8.1988

Here are two pictures of the two points levers connected to rodding, both in their normal position. The left one is labeled only with the number 3, but the right one has the full inscription "Aiguilles 1/2^b", i.e., "points 1/2^b":

Points levers 3 and 1/2^b, St.Blaise CFF, 17.8.1988

The left lever has a temporary lock because the catenary of track 3 is switched off and grounded: The tags say "Voie 3 interdite" ("Track 3 prohibited") and "Attention | Ligne à la terre" ("Attention | Line at ground"):

Points levers, St.Blaise CFF, 17.8.1988

Here one can see the line block instruments. The outer instruments, connected to plunger locks above, are the instruments for "blocking back" (signalling line clear), the inner ones for "Blocking ahead," i.e., signalling line occupied. I do not think that these instruments were connected to the route levers, so there was no electric route locking here.

Hanspeter Thöni: In Switzerland, small station with mechanical frames typically did not have electric route locking. One such case was Au ZH [in the canton of Zurich], where one set of points was far from the signal box. A direct current lock was used to lock the route lever. In other cases, electric locks were added when semaphores were replaced with colour light signals, however, the locks would lock the signal levers directly. This created the problem that the signal lever could not be returned to stop in case of an emergency, and therefore, two buttons were added on the lever lock:

• Emergency stop.
• Emergency release (sealed).

Two such buttons per signal show that a signal lock has been added – but here in St.Blaise, electric route or signal locks were still missing:

Block instruments and route levers, St.Blaise CFF, 17.8.1988

We will take a look at the possible routes below, but before that, I want to point out the special lever on the very right with the following tag (I cannot decipher the small numbers above the route letters, therefore I used question marks):

• Apparell et Block en service | Manoeuvrer leviers de parcours a^?, c^?, d^?, b^?
• Position intermédiaire. Manoeuvrer leviers de signaux A¹, C¹, A^d, D¹, B¹, D^d.
• Apparell et Block exclus.

Translated:

• Interlocking and block in service. Operation of route levers a^?, c^?, d^?, b^?
• Intermediate position. Movement of signal levers A¹, C¹, A^d, D¹, B¹, D^d.
• Interlocking and block out of service.

Lever to lock interlocking, St.Blaise CFF, 17.8.1988

The label seems to indicate that this lever must be put into the intermediate position before signals could be cleared. However, the next picture shows that this is not the case: The signal levers D^d, D^1/2 and B^1/2 are reversed and point downwards, but that locking lever is still pointing upwards, i.e., towards "interlocking and block in service."

Hanspeter's answer: This is the lever for switching out the station from the block line. Let me call it "switch-out lever". Switching out means:

• The block section extends from the previous to the next signal box.
• All through signals are cleared.
• The station is, so-to-speak, no longer existing.

Switching out the signal box:

1. Ensure that all block sections are unoccupied (all block instruments in normal position);
2. By telephone, ensure that no trains are allowed to leave into the sections;
3. Now follow the instructions near the lever: Reverse route levers a², c², d¹, b¹, i.e., the through routes on the main tracks.
4. Now, the switch-out lever is moved to the intermediate position. This interrupts the electric block lines. Now, all signals can be cleared (A¹, C¹, A^d, D¹, B¹, D^d; "1" means "Fahrbegriff 1," i.e., maximum speed). Then, the switch-out lever can be moved to its lowest position, which locks the signal levers and connects the electric block lines of the two neighbouring signal boxes.
5. Inform the neighbouring stations that the station is now out of service and unmanned.

Reverse switching out:

1. Call neighbouring stations to ensure that block sections are unoccupied and no trains are permitted to leave.
2. Return switch-out lever to intermediate position.
3. Return all signal levers to stop.
4. Return switch-out lever to upper normal position.
5. Return route levers to normal position.
6. Inform neighbouring stations.

However, there is one problem for which I [Hanspeter Thöni] do not yet have an answer—and as no such installation do exist any more, no-one might be able to answer this question: Clearing the starting signal engages the "repeat lock" at the block instrument, whose purpose is to prevent clearing the starting signal twice—but this would also prevent clearing the same signal after reverting the station's switching out! I do see two ways to overcome this problem:

1. The intermediate position of the switch-out lever unlocks the repeat lock; but I consider this solution a difficult one.
2. The intermediate position connects the block instruments in such a way that after returning the signal levers, blocking the "line occupied" instrument and then blocking the "line clear" instrument would return the repeat lock to its normal position. However, this would additionally require a release of the plunger lock.

(A similar lever is the "king lever", which I have shortly described in this posting about the Epping-Ongar Railway; it is interesting to notice that the steps for switching out are very similar to what Hanspeter describes above.)

Interlocking frame, St.Blaise CFF, 17.8.1988

On the track panel one can see that the green lamps are lighted near the signal symbols D^1/2 and B^1/2:

Another detail which I do not understand is how the two-arm semaphores were operated: There is only one lever for each of them, so a single lever must be able to move its signal to two different positions. Of course, with the removed tracks, clear with two arms ("Fahrbegriff 2," i.e., clear for 40 km/h) is no longer necessary—but certainly, we still see the levers as they were built for the full station including the loop track 3, and therefore, these levers alone must be able to clear each signal either for full speed (one arm) or for restricted sped (two arms). But—how? After studying the levers and the gears at the signal, my assumption is that the lever of the distant starter might control what happens at the home signal ...

... but this is wrong, as Hanspeter writes: The signal levers are so-called "reversing signal levers." One can see the small coupling levers mounted near the label of each such lever. If the coupling lever is pointing upwards, the signal clears with one arm, if the coupling lever is pointing downwards, the signal clears with two arms. The labels, therefore, have to inscriptions::

• Above the separator line, "Fahrbegriff 1" (e.g. A¹) is shown, in addition to the respective routes.
• Below the line, "Fahrbegriff 2" is shown with its routes.

In order to move the signal in two different ways, the rotation of the wheel at the lever that bears the rope is reversed; and also the locking bar in the locking bed is moved in one of two directions, either upwards or downwards. This guarantees that the locking bed takes part in the decision of the number of arms cleared. The slotted wheel at the signal can be in 5 positions: Stop—one arm raised—stop—two arms raised—stop. The normal position is the central one, and depending on the direction in which the wire turns the wheel, one or two arms are cleared. The outermost stop positions are only relevant when one of the wires breaks.

Two scans by Hanspeter show these levers with some more details. The reversing gears proper are still unclear from them, but Hanspeter sent me a series of pictures and a video of such a lever and its interesting internals, which I will show in a later posting!

The following detail from a picture above shows that there are exactly six levers for the six signals (four stop signals and two mechanical distant signals), so that this frame type does not use double levers like e.g. the German standard type ("Einheitsstellwerk"). Moreover, one can see that the two middle levers do not bear ropes, but only brakes that are tensioned by springs. The reason is if course that the starting signals have been replaced with colour light signals:

Detail of interlocking frame, St.Blaise CFF, 17.8.1988

The plate of Hasler of Bern can be seen squarely. Obviously, the block instruments were licensed from Siemens, as they look exactly like their German counterparts. So, I do not believe that anything inside this box is "patent of Hasler," as the plate claims. Hanspeter adds that the type of the frame is quite clearly Bruchsal J:

Builder's plate on block instruments, St.Blaise CFF, 17.8.1988

After multiple points had been removed, the number of possible routes has of course decreased. However, there is still one more route present than would be typical elsewhere:

• d¹ de Cornaux sur voie 1 | D¹
• c² à Cornaux de voie 2 | C¹
• b¹ à Neuchâtel de voie 1 | B¹
• b⁵ à Neuchâtel de voie 5 | 4/Sb. | B²
• a² de Neuchâtel sur voie 2 | A¹

Also here, there is a signalled route out of the loading track 5; however, the track can only be left towards Neuchâtel.

Above the route levers, one can see again the 'virutal track occupation indicator' (see Grenchen Süd). Here, this indicators are actually useful: On the track plan, one can see that the main tracks are shown in white, i.e., they are not track-circuited. Only the yellow tracks (points and short sections near them) do have track circuits. Still, the virtual occupation indicators are more a reminder than a safety-critical feature. Therefore, a visual check whether a track is free is still required before a corresponding signal is cleared.

Route levers, St.Blaise CFF, 17.8.1988

Here, one can see the complete frame, with the signals cleared for a through train:

Interlocking frame, St.Blaise CFF, 17.8.1988

Last, I took two random pictures of an electrical cabinet.

Some fuses are sealed, because their removal could allow unsafe manipulations. The fuses on the left are made from ceramics, they are used for control circuits. On the right, 1 amp fuses are used for signal lamps. In case of a shortage, they must interrupt very safely, so that the signal circuits will show the disruption in every case:

Schaltschrank with fuses, St.Blaise CFF, 17.8.1988

Fuses, St.Blaise CFF, 17.8.1988

So much for this frame—the next posting will show some points and signals of this small station!