Friday, December 27, 2019

Electro-mechanical lever frame at Albacina, 1990

Deutsche Version dieses Postings

On one of the next days, we made a trip to Macerata via Albacina. Here is the first handful of photos, up to Albacina.

The first two pictures show signals for a level crossings ("segnale di protezione di un PL", where PL means "passaggi a livello", i.e., level passage). Similar to FS's signal book, I show them in reverse order, because the signals were for different crossings. The first signal is a protection signal proper (segnale di protezione) indicating that the barriers are closed and hence the track is free (via libera):

Level crossing protection signal, Cancelli di Fabriano, May 1990

The second one is the corresponding distant signal (segnale di avviso), which tells the driver that the following protection signal will show "via libera" (avviso di via libera):

Level crossing protection distant signal, Cancelli di Fabriano, May 1990

Rusty tracks contained some old steam locomotives—I think this was at the junction station Fabriano, but I'm not really sure:

940.006, Fabriano?, May 1990

Steamers, Fabriano?, May 1990

At Albacina I was allowed to take photos of the lever frame, an electro-mechanical one like the one at Ciampino::

Lever frame, Albacina, May 1990

Lever frame, Albacina, May 1990

At the upper right, one can see the line block instrument—it looks brand-new and quite British. Here is an enlargement from the first of the previous images, without any more explanations, as I don't know the details of its workings (a nice picture of a similar instrument is show in the master's theses "Il Segnalamento: Principi e Tecnologie per la Regolazione del Traffico Ferroviario" by Ludovico Zampiero from 2016, which can be found on the internet as a downloadable file):

Block instruments, Albacina, May 1990

A work train occupied on of the tracks:

Work train with diesel locomotive, Albacina, May 1990

This starting signal (for the track on the right of it) can show digits 1 or 2, depending on whether the train departs on the left line towards Falconara or the right one to Macerata:

Starting signals, Albacina, May 1990

A zoom of the signal to the left of it (click on the picture shows it in full scan resolution) surprisingly reveals that also this signal can show both digits—even though it is not possible to traverse to the track to Macerata from there:

Starting signals, Albacina, May 1990

Here is the somewhat shabby station building:

Station building, Albacina, May 1990

And here is a last image of the lever frame. Signal or track relays are placed even above the frame—somehow, it seems that the signal box became too small at some point:

Lever frame, Albacina, May 1990

1 comment:

  1. The red block instrument seen above was introduced in 1938. Its functioning is based on bell codes and polarity reversals and reminds British practice. The usual setup involves two instruments, one for each direction. The station pictured above was most obviously at the boundary between an automatic and a manual section. In fact the base of the missing instrument could still be seen on the top left corner of the lever frame. If I'm not wrong, nowadays (2020) this kind of manual block working is still in operation only on two minor lines north of Milan, and on some section of the Rome-Sulmona railway.

    The instrument has two rotating handles with pushbuttons and three mechanical indicators. The two pushbuttons are mechanically linked together. The left side of the instrument (left handle and indicator) is used to request permission to send a train to the adjacent station or block post, the right side is used to grant such permission. On single-track lines the instrument has an additional internal interlock preventing the simultaneous operation of both handles. Once a train enters the section towards the next station or block post the instrument gets locked and remains in that state until the train leaves the section. The third indicator (the lower one) turns green when the instrument gets unlocked and the right handle could then be returned to its normal position. Below the third indicator there is a round red cover closed with a numbered lead seal protecting a pushbutton that could be used to manually unlock the instrument in case of failure.

    At stations the instrument simply unlocks sspecific frame levers, at intermediate block posts that do not require any additional lever (e.g. for some nearby level crossing) the left handle of the instrument could be used to directly control the distant and home signals of the post.

    If you want to know the exact detail of its operation let me know in some way :)

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