Friday, May 31, 2013

A few Italian signals and an interlocking panel, 2012

After a first posting about Italian points, here is another one with a few Italian signals and an interlocking.

The Serchio valley line from Lucca to Aulla is remote controlled throughout. At Fornaci di Barga, I could take a picture of the local, unmanned interlocking:

Interlocking, Fornaci di Barga, August 2012

Here are some lights going on and off during a train run: A train is coming from Aulla, which is on the left (one can see the connection to the industrial spur shown in my previous posting). Two lower lamps are lighted which are probably indicating route locks; a lamp at the upper right (to Lucca) seems to indicate "line clear", whereas the dark lamp from Aulla means "line occupied":

Interlocking, Fornaci di Barga, August 2012

A short time later, the train is coming into the station. The lamp "from Aulla" is now on ("line clear"), whereas one of the lower lamps is extinguished ("route unlocked"):

Interlocking, Fornaci di Barga, August 2012

The train arrives at the platform:

ALn663 1144 as train R6969, Fornaci di Barga, August 2012

After the train has departed, both lower lamps are off (both routes unlocked ...), and the lamp "to Lucca" is now dark, as the line is now occupied, I'd say:

Interlocking, Fornaci di Barga, August 2012

Behind the interlocking, there is this nice triple clock. All of them are out of order, and I do not understand why three were needed in the first place:

Clocks, Fornaci di Barga, August 2012

On a few trips in the vicinity of Lucca, I took some photos of signals. Italian signalling is not that hard to understand after recognizing that (a) a red light over non-red lights means "slow"; and "moves down" the other lights by one signal head; and that (b) "slow" signals originally did not show the expected speed at the stop signal, but only at the previous distant signal; however, today, one or two white bars are used to indicate the expected speed also at the stop signal. Some explanations can be found here and here.

Italian light signals are "searchlight signals", i.e., they show different colours through one lens. In earlier times, a small mechanical device moved coloured shades into the light path. Today, semi-transparent mirrors are used, or alternatively LEDs. The first two methods are shown on this web page.

The following picture shows a starting signal at Lucca for the line to Aulla. The number "1" is a route indicator ("first" route, counted from the left). The triangle below another signal means "green means slow with 30 kph":

Starting signals towards Aulla and Florence, Lucca, August 2012

And here is the train:

ALn663 1147 as R6962, Lucca, August 2012

By the way, the interlocking of Lucca and signals in Aulla are shown on this page at signalbox.org.

The following signals are at Fornaci di Barga.

Starting signals towards Lucca, Fornaci di Barga, August 2012

At the opposite end, the starting signals are mounted on this signal bridge:

Starting signals towards Aulla, Fornaci di Barga, August 2012

Here is the rightmost starting signal. Apparently, LEDs are used in the signal head. However, I do not know what the black intercepting box contains ...

Loop starting signal, Fornaci di Barga, August 2012

Here is the same signal, with the "30 kph triangle":

Loop starting signal, Fornaci di Barga, August 2012

The last bay but one at Lucca has this signal. Below it, one can recognize the route indicator for the lines to Pisa (1) and Viareggio (2):

Starting signal, Lucca, August 2012

Near Florence, I caught this signal: Slow entry (upper red), maximum speed at next signal (lower green):

Signal, Firenze Rifredi, August 2012

And here is the most famous Italian signal, the "Christmas tree": Red and yellow and green at the same time!
  • Upper red = slow (actually "diverging route"); in this case, there is a bar below the signal, which indicates the allowed speed at this signal: One bar means 60 kph.
  • Yellow and green = slow with 30 kph at next signal.
"2" is the route indicator ("second track, counted from left"), "EST" is "esterno" ("outermost", i.e. home signal), but I do not know what "COD" means (cab signalling in place??):

"Albero di Natale" (Christmas tree), Pisa San Rossore, August 2012

Some Italian points, 2012

In 2012, we spent our holidays in Tuscany, near Lucca. Here are two postings with a few railway photos from that August. The first is about points (or switches, as the Americans call them) and a few other "things at tracks."

Here is the layout of the small station Fornaci di Barga in northern Tuscany, at the remote-controlled line from Lucca to Aulla through the valley of the Serchio river. The pink tracks have not been used for a long a time. The numbers of the points are my guesses from various letters on point machines or the like—they might actually be different:


There are only two tracks, a main track and a loop:

Fornaci di Barga, August 2012

The northern (Aulla) side is somewhat overgrown in summer. The points in the foreground are number 5:

Fornaci di Barga, August 2012

Fornaci is the place of numerous meets, therefore the points are kept shiny—but only on one side:

Points no.5, Fornaci di Barga, August 2012

A lock, which probably will never again be unlocked, guarantees that the points remain in the correct position for running movements. The blades of double slip number 8 most probably are dependent on points number 5, so that they provide flank protection for trains. Therefore, in addition to the empty lock (which locks the blades), there is another key which can only be removed when the points are lined up for the industrial tracks; and which is then used to unlock number 8:

Points no.5, Fornaci di Barga, August 2012

The hook near the lock is part of a simple blade lock. Here is the hook for the other blade. For simplicity, the counterpart of the hook is the rail base. At the top, there is the locking bar to the locks shown above:

Points no.5, Fornaci di Barga, August 2012

Points no.5, Fornaci di Barga, August 2012

Here are, once more, the points including the weight on which the number "5" is barely readable:

Points no.5, Fornaci di Barga, August 2012

Finally, here is a nameplate, probably from an overhaul some 25 years ago:

Points no.5, Fornaci di Barga, August 2012

The next points are the ones leading into the loop, numbered D1:

Points D1, Fornaci di Barga, August 2012

In contrast to the old external blade locks at points no.5, Italian electric point machines use internal blade locks. However, this sort of blade locks requires that the point machine is fastened very securely to the tracks. Here, one can see the necessary steel T bars:

Points D1, Fornaci di Barga, August 2012

As each blade is locked separately inside the point machine, there is a separate bar leading from the drive to each blade. Near these bars, there are separate locking bars which are used to check the position of the blades inside the drive:

Points D1, Fornaci di Barga, August 2012

This picture shows, in the background, the fouling point indicator of points no.5—a simple white beam between the rails meeting at the frog:

Points D1, Fornaci di Barga, August 2012

Finally, here are the double slip points (double slip switch) that have fallen into disuse long ago:

Double slip points, Fornaci di Barga, August 2012

The following picture shows, in the foreground, the lock mentioned above, which is necessary because of flank protection. Also these blades have blade locks using hooks below the rail base. One can also see some terminal box in the background and some cables, but I don't know their purpose (I didn't want to disconnect them and wait for some effect ...):

Double slip points, Fornaci di Barga, August 2012

Double slip points, Fornaci di Barga, August 2012

The opposite blades of the double slip points do not have blade locks:

Double slip points, Fornaci di Barga, August 2012

Double slip points, Fornaci di Barga, August 2012

Here are remaining parts of the double slip points, which had all us railway freaks puzzled when we were young:

Double slip points, Fornaci di Barga, August 2012

Double slip points, Fornaci di Barga, August 2012

The ensemble at Fornaci also contains somewhat desolate (but maybe still functional) track scales:

Track scales, Fornaci di Barga, August 2012

Track scales, Fornaci di Barga, August 2012

Here is another point machine, this time at the Lucca station. Also this picture shows that the blade locks are inside the drive, which is therefore connected to the rails with heavy steel sections:

Points D28, Lucca, August 2012

Points D28, Lucca, August 2012

Finally, here is a double insulated joint, also at Lucca:

Insulated rail joints, Lucca, August 2012

For what, however, one needs two double insulated joints side by side, I do not know:

Insulated rail joints, Lucca, August 2012

Insulated rail joints, Lucca, August 2012

Sunday, May 26, 2013

My Austrian type 12SA lever frame: Locking the distant signal

Here is the last lock type of the 12SA interlocking: The simple lock between a home signal and its distant signal.

Of course, the distant signal had to remain in the "stop" position as long as the home signal was also not "clear." This rule was enforced by a simple bolt that moved into a hole either in the chain wheel of the home signal lever or of the distant signal lever. Here is a short video that shows how the home signal and then the distant signal is moved to "clear:"
  • First, the home signal lever is reversed.
  • Then, the small bolt is moved to the right with a small lever. Now, the home signal lever is locked, and the distant signal lever is free to move.
  • Finally, the lever of the distant signal is reversed.

Clearing home and distant signal

Here is a sequence of images showing the same operation:

Normal position

Clearing the home signal

Clearing the home signal

Clearing the home signal

Reversing lock lever

Clearing the distant signal

Clearing the distant signal

When the signals are returned to their normal "stop" and "stop expected" positions, the levers are moved the other way round:

Returning distant and home signal

On my 12SA, similar locks were also used between the fouling bar levers and the home signal levers. This was necessary so that the electric lock (described in the previous posting) would have to be engaged before the corresponding home signal could be cleared.

On small signal lever installations, this sort of lock was also used to prevent that the opposing home signals could be cleared at the same time. Here is an example from the small town of Horn in Lower Austria, where home signal A is "clear," while the lever of home signal Z is locked in the downward "stop" position:

Home signal levers, Horn, 20.9.1986