Wireless of the Week - week 34
 

If something could wave, buzz, blink or flash it could transmit a message. With the event of morse code and electricity in the late 19th century the army developed battery operated signal lamps controlled by a morse code key as one of its first practical light signalling devices. Lamp signalling had drawbacks. It had to be line of sight between stations and could be intercepted. On the other hand it could be used from cover (unlike semaphore flags), was fast, lightweight, easy to use and even the interception problem was limited by having lamps with narrow beams that could be carefully aimed towards the receiver.

This Canadian lamp was made by Northern Electric Company Limited in 1941. The lamp itself is a “Lamps Signalling Daylight Short Range Projector Mk.II” comprising of a lens, bulb and mirrored parabolic reflector in a cylindrical aluminum body. On the top is a sight for aiming and on the bottom a socket that allows the lamp to be mounted on either a tripod or sectional ground spike. A cable attached to the lamp connects it to the morse key mounted in the wooden carrying case. The brass ring on the back is to lift it out of the case.

The wooden case is a bit of a mismatch as it is from a British lamp made by C.A. Vandervell & Co., Ltd. in 1918. It is 6” wide, 9-1/2” deep and 9-1/2” tall. It has two compartments each with its own lid, one for the accessories, such as the ground spike, lens filters and spare bulbs, and the other for the battery. The morse key is attached to the underside of one lid and an instruction plate to the other. The lids have a canvas lip to prevent water from entering.

Operating the lamp was very easy. All the signaler had to do was set the lamp up on its spike or tripod, hook up the battery, aim it towards the receiving station and begin tapping out his message on the key.

Despite lamp signalling being practical, one gets the impression that during WW2 its biggest use was not so much on the battlefield as it was for training new Signal Corps recruits on the parade square

I'll keep a lookout for a C.A.V. lamp for you. :)

The WW1 "Lucas Lamp" had a wooden case, as you've got there, and was designed by one Captain Lucas (no relation to Joseph "Prince of Insufficient Light" Lucas, the automotive electrics manufacturer) as a replacement for the oil-fired "Lamp, Signalling 'B'". They work well and are a vast improvement on the oil lamp (with electric torch for the signaller) that they replaced.

Originally there was a standard 12-volt dry battery for the lamp, but this was replaced by 8 of the standard field telephone cells (X or S) connected in series.
(They were a stock item, the S (inert) cells could be stored for long periods, and it was one less thing that had to be supplied.)

The WW2 version was very similar, except that the British one used a pressed-steel case (Canada exported timber so continued with wood), and there was a spare battery case that contained 16 X (or S) cells - enough to make two complete 12V packs for the lamp.

Other versions:

1) Lamp, Daylight Signalling, Long Range - this used a larger (5") lamp and was powered by a 10 volt 16 amp hour accumulator.

2) Lamp, Daylight Signalling, Short Range (Mounted Services) - the cavalry version in two leather cases (for a balanced load).

3) Lamp, Daylight Signalling, Lightweight. Too late for WW2 and almost immediately obsolete. All fitted in a canvas satchel and the lamp had two handgrips (one with a push switch for signalling) and had a spigot to allow it to be mounted on a bayonet for the No.4 rifle. The battery compartment contained the usual morse key for use when the lamp was not being hand-held.

Apart from the "lightweight" lamp, all of these were intended for use as an alternative to the heliograph (at night or when cloudy) and fitted the standard tripod. (Stand, Lamp and Heliograph.)

The bulbs used are 'special', being mounted on a stalk to position them at the focus of the reflector (so the short and long-range lamps need different bulbs). You can run the lamp quite successfully from a pair of 996 lantern batteries - the internal cells are the same ('F' size) as the ones in the post-WW2 'X' cells.

(I must admit that I'd really like a lime light, but it would be difficult to assemble the rest of the kit (goatskin bags for the oxygen supply) and ordering large quantities of potassium chlorate :eek: would get the police taking an interest in me.) :(

Chris.

globes
 

At a hamfest years ago, a chap gave me a box full of those stalk 10V bulbs for the Lucas lamp, must have been 100+ ( Osram brand ? ). I have a few left somewhere. I sent most of them to a chap in the UK for free , he was using them in his scout troop .

A guy I knew in our MV club worked for the Govt. survey mapping dept. , they used those lamps as survey markers for the theodolite over long distances .

BTW those lamps were also made here , I have a complete set . Aussie disposals had the tripod mount NOS , I bought two of them .

A quick cautionary note: the long-range lamp has an asbestos pad behind the mirror, so be careful if you ever need to dismantle one.

Chris.

hello
Thanks for all informations
kind regards
daniel from france

Srsl
 

I'm really enjoying your series of images and articles Bruce, thanks for your efforts.
Informative stuff.

My contribution to the Short Range Signal Lamp...

WW1 Lucas.
The suppliers plate is interesting.
The Spares box is tin and is actually a CAV item...but the contents are cool.

I love the Broad Arrow marked bulbs
As Chris mentioned they are quite specific to the application.

Brent
NZ

CAV lamp
 

Hi Bruce,
I have a surplus WW1 CAV lamp if you want it?
the box is much tattier that yours but the lamp is in really nice condition.

Lamp with or without box is yours.
there are no other ancillaries included.
I'm sure you will have something to swap to increase the loading on my shed floor ;-)

Well you sure have my attention!!! I expect shipping from where you are (bottom right) to where I am (top left) makes sending just the lamp alone seem more practical. Just for fun I checked the serial number on my CAV box...68419, a mere 873 lamps away from your 67546.

Now what-oh-what I can send you that will crack your garage floor I wonder????