Railway Signalling in Burma - Part 1: Semaphore Signals

In the 19th century, Myanmar, then known as Burma, was administered as part of 'British India'. The British built the extensive metre gauge railway network so it’s not surprising that the signalling installed largely followed British practice.

But the surviving semaphore signals are a very odd collection. I imagine that this is at least partly the result of Burma being cut-off from the West during the 50 years of military rule. What's visible now gives the strong impression of being cobbled-together on a 'make-do-and-mend' basis from whatever was available.

The British Legacy

I've not travelled widely on the railways in Burma, but I try to keep a look-out when in the country. The best example of a 'typically British' signal I've seen so far is at Bago.

A 'typically British' lattice-post bracket signal at Bago.

Although the stop signal arms are red with a white band on the front, a further embellishment is provided in Burma. There are two circular 'spots' in white, one on the left, the other on the right of the white stripe. A small square in the 'spots' reveals the red arm colour. It's hard to resist the conclusion that this elegant bracket signal was built in the U.K. and shipped out to Burma (although the mixture of upper-quadrant main arms and lower-quadrant subsidiary arms is puzzling).

Made in Burma

Elsewhere, signals show little standardisation as if each application was built from scratch with whatever was to hand.

A curious stop signal in between Bago and Kyaikto.

A fairly extreme example is shown above. First, the signal post appears to be a rolled section, probably 'T' profile. A pivot for the signal arm has been fitted right at the top of the post and there is no finial. The signal arm looks 'second-hand' and it carries the two 'spots' described above. It appears to be bolted to a casting which would normally include the 'spectacle' carrying coloured glasses allowing the signal to display a coloured indication at night. In this case, the casting has no spectacle but the shape of a typical lower-quadrant 2-aspect spectacle frame has been made out of steel rod. I can't see the function of this frame - the 'spectacle frame' is too thin to improve the signal sighting, no signal lighting is provided so there are no coloured glasses and it's certainly not aesthetically satisfying. A lower-quadrant signal arm mounted like this just looks 'wrong' (and this arm-and-spectacle combination is a mirror-image of a British lower-quadrant). The signal in the picture is displaying a (very poor) upper-quadrant 'Off' indication. The signal is controlled by a conventional wire and pulley system from an associated single-lever ground frame. Pulling on the wire lifts the balance weight and the balance weight bar moves the push rod so as to lift the arm. A signal ladder has been provided, but it's of rather lightweight construction.

There seem to be endless variations on this theme. Some signal arms are tapered towards the pivot (as in typical American practice). The two white discs with the square 'hole' are still provided but, particularly on tapered signal arms, one 'spot' is sometimes deformed into an oval. Sometimes, a spectacle frame is provided, cut from steel sheet. Although all the signals I've seen are apparently 2-aspect, these cut-out spectacles appear with both two- and three- holes. No lighting is provided and there are no coloured spectacle glasses.

Upper quadrant signals at Bago with 'lower quadrant' arms.

At Bago, there are two signals of this pattern side-by-side, one with a 2-hole cut-out spectacle, the other with 3-holes. Both these arm-and-spectacle combinations are as in British practice (not mirror image) so, when arranged as an upper quadrant, look very odd when 'Off' (and couldn't easily provide the normal feature of the spectacle by changing the colour of the signal indication at night).

These two signals (like many others) are lattice-post - the remains of earlier signals, I suspect. Lattice posts look odd without a finial but most of them have disappeared. Other variations on signal posts include steel tube and, particularly for taller posts, two rolled sections (or rails) connected to form a built-up post. The example below has a built-up post surmounted by a tubular section and a finial. The arm of this signal has a nicely-proportioned spectacle made out of rod. As far as I can see, the push rod from the balance weight bar mounted fairly high would actually operate the arm as a lower-quadrant but the arm remained stubbornly 'On' as we rolled past! I'm not sure I'd be happy to use the rather lightweight signal ladder provided on this tall signal.

Tall signal with built-up post and tubular section.

Motor operation

Between Yangon and Bago, there a pair of motor operated semaphore signals - a down distant followed by a down outer home. Both signals had tapered (American-style) arms with 3-aspect spectacles and the rear of the arms was black with the chevron or bar white!

The Bracket Signal

Most of the network remains single track with passing loops, although around Yangon and on main lines there's double track which is still being extended.

At passing loops, there's normally a splitting home signal at each end of the station, situated at the toe of the points, allowing movements onto either Main or Loop line.

Typical 2-doll bracket at a passing loop between Bago and Kyaikto.

The picture above shows a typical 2-doll equal bracket. The main post and platform is fabricated from rolled sections but the dolls are lattice construction. The signal arms and pivots appear second-hand but the 'spectacles' are fabricated from rod - that on the left appears to be covered with gauze. Back blinders (which, on a signal with lighting, obscure a white 'back light' when the arm is 'Off') have been fabricated from sheet and rod, but there is no lighting. The arms are arranged as lower-quadrant and the right-hand arm is (sort of) 'Off'. The arms are operated by push rods from rocking shafts on the signal platform. The rocking shafts are operated by push rods from the ground, interlocked with the loop points. Normally, a single lever operates the signal with the appropriate arm 'selected' by the points interlock. The disc on the main post was once a speed restriction sign. The 'pointsman' is displaying a steady green flag.

Upper-quadrant 2-doll bracket signal at entrance to loop from the south at Naba.

Elsewhere, similar 2-doll brackets are provided as splitting home signals at the entry to loops but with the signal arms arranged as upper-quadrant, as the example shown above.

Photographs

Burma: Semaphore Railway Signals.

The above set of pictures is part of a Collection Railways in Burma.

Road Repairs

The Wirtgen W250 Cold Milling Machine.

A stretch of road near me in Brewood had been 'patched' many times over recent years. Apart from the remarkable number of private cars the village seems home to, this road carries our bus service, the delivery vehicles servicing our local shops and a terrifying variety of agricultural machines, often with large trailers. As a result, 'patching' gave only brief improvement before the surface started breaking up again.

At the beginning of November, a circular was put out by the Council saying that the road in question was being closed for 8 days for essential work. So I was not surprised when I got up on 8th November to hear the muffled roar of a large diesel engine. I was quite impressed by the sight of the large yellow machine parked outside which was producing the sound. I recognised it as a 'Road Plane' and had a vague idea of its function in removing an old road surface but realised I knew little more and had not seen one operating. I had a closer look and spoke briefly to the machine operator as he filled the machine's water tank from a Fire Hydrant. The sheer size of the machine, carried on four tracked 'bogies', was notable as was the proliferation of colour computer screens provided to control the vehicle.

The machine was labelled as a Wirtgen product but it was being operated by Power Plane Limited. The machine was labelled as a 'W250' and the Power Plane website has brief details here, with links allowing download of two Wirtgen Documents in PDF format - the Technical Specification for the machine and a description of its use.

Before long, the machine in Brewood was demonstrating its ability to remove the old road surface by Cold Milling. I found the speed and accuracy of the process impressive.

The W250 at work.

In 1961 Reinhard Wirtgen, then aged 20, set up a haulage firm with one lorry. He developed the business into a construction firm, developing hydraulic shears for demolishing concrete structures and producing his own machines for road repairs. In 1970 he introduced 'Hot Milling' as a method for removing worn road surfaces and later 'Hot Recycling' as a method of repairing roads. 'Cold Milling' was introduced in 1979 and the business gave up contracting to concentrate on building machines at Windhagen, Germany. The Wirtgen Group now supplies machines worldwide and, in addition to Cold Milling machines, produces machines for Soil Stabilisation, Cold Recycling, Hot Recycling, Slipform Paving and Surface Mining. I'm afraid my ignorance of these techniques is almost total but the Wirtgen Site is a useful primer.

The W250 made short work of removing the old road surface, allowing other machines to lay the replacement surface. It was the massive yet sophisticated W250 which captured my imagination, but I should perhaps mention the Bomag BF600P Asphalt Finisher. Links on the Bomag webpage allow download of a leaflet and datasheet for this machine.

The Bomag BF600P Asphalt Finisher.

Bomag is a German company started in 1957 but it is now part of the much larger French group Fayat.

Photographs

Cold Milling Machine for Roads.