Switzerland 1988: Some details of the interlocking apparatus on signal box 2 at Biel RB

Deutsche Version dieses Postings

As I have promised in the last posting, here is a list of some facilities of and around the interlocking frame on Biel RB's signal box 2.

1. On the far right, there are two approval block instruments for train routes at signal box 1:

• Freigabe nach Stellw. I nach Mett ab Gl. 1-23 ("Approval to SB I to Mett out of track 1-23")
• Freigabe nach Stellw. I von Mett auf Gl. 1-23("Approval to SB I from Mett into track 1-23")

Above these instruments, there are plunger locks, but I do not know why:

Signal box 2, approval for routes from and to Mett, Biel RB, 23.8.1988

The instruments connected to the ones above are a multitude of single block instruments at signal box 1. The following picture shows only those for routes to Mett, and one can see that some instruments are used for single tracks, whereas others are for track pairs, and one is for tracks 12 to 23:

Signal box 1, block instruments for routes to Mett, Biel RB, 23.8.1988

2. On the other side, signal box 3 must agree to some routes at signal box 2. For this purpose, signal box 2 has three instruments:

• von u. nach Biel P.B. oder Brügg Zustimmung vom Stellwerk III i^IV-VII über W 42 ("from and to Biel main station or Brügg - approval from signal box 3 - i^IV-VII via points 42")
• von u. nach Biel P.B. oder Brügg Zustimmung vom Stellwerk III i^V-VIII über W 35 ("from and to Biel main station or Brügg - approval from signal box 3 - i^V-VIII via points 35")
• von u. nach Biel P.B. oder Brügg Zustimmung vom Stellwerk III i^IX-XII über W 35 ("from and to Biel main station or Brügg - approval from signal box 3 - i^IX-XII via points 35")

Signal box 2, approval block instruments, Biel RB, 23.8.1988

Curiously, there are only two corresponding instruments at signal box 3, which distribute the various routes differently between them, as one can see from the labels on them:

• Einfahrten von Biel P.B. u. Brügg Zustim. nach Stellw. II i^V-XII über W 35 ("Arriving routes from Biel main station and Brügg - approval to signal box 2 - i^V-XII via points 35")
• Ausfahrten nach Biel P.B. u. Brügg Ein- und Ausfahrten von u. nach Depot Zustim. nach Stellw. II i^IV-VIII über W 42, o¹, o², k³, a / b "Departing routes to Biel main station and Brügg, arriving and departing routes from and to Depot - approval to signal box 2 - i^IV-VIII via points 42 - o¹, o², k³, a / b"

Signal box 3, approval block instruments, Biel RB, 23.8.1988

3. Bell plungers and bells for signal box 3 for requesting and returning approvals

The middle row (between the block instruments below and the bells above) contains seven bell plungers. Only four of them are still operational:

• Zustim. von Stellw. III i^IV-VII über W 42 ("[Request] approval from signal box 3 i^IV-VII via points 42")
• Zustim. von Stellw. III i^V-VIII über W 35 ("[Request] approval from signal box 3 i^V-VIII via points 35")
• Zustim. von Stellw. III i^IX-XII über W 35 ("[Request] approval from signal box 3 i^IX-XII via points 35")
• Zustim. von Stellw. III von u. nach Depot ("[Request] approval from signal box 3 from and to depot")

Signal box 2, bell plungers, Biel RB, 23.8.1988

Alas, I did not take pictures of the bells on the opposite side, i.e., on signal box 3—one can only see their bolted brackets in the next picture. On the other hand, two other bell plungers can be seen, whose purpose was most probably to request the unblocking of the approval block instruments by signal box 2:

Signal box 2, bell plungers, Biel RB, 23.8.1988

In turn, signal box had corresponding bells—however, there are three of them. But the rightmost is missing the chain for pulling up the lid, therefore I assume that it was not used any more. The other two bells correspond to the two block instruments on signal box 3, i.e., the approvals for routes via points 35 or 42, respectively:

Signal box 2, bell plungers and bells, Biel RB, 23.8.1988

This concludes the communication devices between the two signal boxes, but there were other devices:

4. Two block instruments and a button lock for line block working towards Biel main station

Signal box 2, block instruments, Biel RB, 23.8.1988

5. Track buttons (whose purpose I do not know)

The buttons have labels "BbT" and then a track number in Roman numerals, i.e., BbTI, BbTII, ..., BbTXIV und BbTXXIII.

Signal box 2, track buttons, Biel RB, 23.8.1988

6. A sealed button SIU for home signals K, N, and O:

Explanation by Hanspeter: SIU is still used today, it means 'Signalfahrtstellungs-Isolierungs-Umgehung' ("Track circuit bypass for signal clearing"). This allows to clear a signal if a track circuit relay erroneously does not pick up.

Signal box 2, SIU button, Biel RB, 23.8.1988

7. As on box 1, there is a toggle switch 16²/₃-Hz – manual inductor:

Signal box 2, block instrument supply selector, Biel RB, 23.8.1988

8. Another set of buttons and/or lamps, which I could only enlarge quite blurred and whose purpose I do not know:

Signal box 2, ???, Biel RB, 23.8.1988

9. And to the left of the block instruments, there is a box with buttons for light shunting signals and bypass buttons for track circuits:

Signal box 2, shunting signal controls and track circuit bypasses, Biel RB, 23.8.1988

At last, there was a small Integra panel on the right, of which I did not take any usable photograph. I suppose it was used for line block working towards Brügg.

The next posting will show some images from and around signal box 3.