THE SIGNAL BOX

OVERSEAS

HESDIGNEUL POSTE 1
Chemin de Fer du Nord

by John Hinson

Hesdigneul signal poste
Photograph by Dr. J W F Scrimgeour 7/61

Looking through Hesdigneul station towards Boulogne, we see Poste 1 on the right. The line nearest the cabin is the St Omer branch, whilst the double track main line passes either side of the island platform. The physical junction between the branch and main line is at Poste 2 which can just be seen at the other end of the station in this picture.

Hestingneul station and Poste 1
Photograph by Dr. J W F Scrimgeour 7/61

A view from the station platform looking towards Amiens. The two block signals for the main line are mounted on the tall post by the signal box and are lowered to the clear position.

Lartigue block apparatus
Photograph by Dr. J W F Scrimgeour 7/61

These huge handles are the Lartigue block apparatus, and are mechanically connected with the block signals seen in the photograph above.

The No1 operating handles are operated when a train departs, and raised the block semaphore signal and also to annonce the train to the next signal box. The No2 handles release the block signal at the box in rear and are operated when a train leaves the section.

This system of signalling was used extensively on the Chemin de Fer du Nord

Inside Hesdigneul Poste 1
Photograph by Dr. J W F Scrimgeour 7/61,

Both of the cabins at Hesdigneul contained were provided with Tyer & Co lever frames. Poste 1 had 25 levers although there appears to be an unnumbered space between levers 15 and 16. Tyer & Co, whilst leading the field in the UK manufacturing signalling instruments, did little trade with the British companies on lever frames but did manage a steady flow for export.

The large chunks of steel attached to the levers are thought to be a means of preventing the operation of the levers by immobilising the catch handle - with so many present here it may be that these views were taken after the closure of the St Omer branch.

Close examination of the window design, with its curved corners to the row of toplights and the main sections, leaves one wondering if the architecture is of British origin too.

Palette SEM signal
Photograph by Dr. J W F Scrimgeour 7/61

It is hard to tell here whether the track is excessively canted, or whether the photographer is leaning, the signal is leaning, or the telegraph poles are leaning!

This photograph shows a Palette SEM signal in the ouvert (clear) position - indicating that the Lartigue semaphore signal at the next box is cleared, thus giving an indication very similar to the distant signal of UK practice. The Palette SEM signal was only found on the Chemin de Fer du Nord.

Between the rails in the foreground is a cab-signalling ramp or crocodile, so called because the supporting legs and ramps at either end make it look like such an animal.

Square purple disc signal
Photograph by Dr. J W F Scrimgeour 7/61

This signal acts as a starting signal onto the single-line branch to St Omer. It is purple in colour, and known as a Carré Violet. It acted as an "absolute stop" signal (as opposed to "conditional stop" signals) and was used to control movements from sidings and goods lines. It was revolved when cleared for a train to proceed. The modern-day equivalent can still be seen in marshalling yards - a purple light signal.

Dr Scrimgeour revisited the location in July 1973, and noted that the junction had been completely removed and the main line controlled by automatic colour-light signals.

Additional notes by David Thomas and Michiel Rademakers

About the photographs



Comments about this article should be addressed to John Hinson