Diver at work using a torch for close illumination.

Diver's Submarine Electric Torches were first developed to give illumination for close examination work. They have to be self contained, the older ones powered by an accumulator type battery which could be recharged. Some models were fitted with a switch to turn the light off saving on the battery power. The lens is of a convex type and magnifies the light. Sometimes there was a protective grill across the glass or prongs to protect the glass from an impact. When fully charged the battery would last about seven hours. Torches are made from non-ferrous metal so as not to corrode in their watery environment.

SIEBE GORMAN SUBMARINE ELECTRIC TORCHES

Siebe Gorman & Co Ltd has been producing hand-held, battery powered, submarine electric torches for divers and the Ministry of Defence
(MOD) since the 1920s. Early torches are shown in the classic book ‘Deep Diving and Submarine Operations’ (1935, 4th ed.) by Sir Robert H. Davis,
and in the recent editions. They are also described in the Siebe Gorman & Co Ltd catalogue: ‘D.5’ ‘Diving Apparatus and Other Submarine Appliances’.

In 1961, the famous diving manufacturer C.E. Heinke merged with Siebe Gorman, and for a short while, torches were made with the
combined ‘Siebe Heinke’ inscription. However this linked inscription was later dropped, with a return to the Siebe Gorman name tag (fig.20).

In 1975, Siebe Gorman moved from their ‘Neptune Works’ at Chessington in Surrey, to a new location at Cwmbran in Wales.
By this time, the manufacture of diving equipment had declined, and the new factory concentrated on fire fighting apparatus.
However, ‘switchless’ diving torches were still made with the Cwmbran address stamped on the casings (fig.14).

By 1995, manufacturing at Cwmbran also declined, and in 1999, BTR and Siebe Gorman merged to form Invensys.
The Royal Navy continued to use their stock of diving torches long after torch manufacturing ceased.

Apart from their features, the four main ‘design types’ of these hand-held, battery operated torches can often be identified and aged from their
official markings. Torches do vary and may have some, all or no official marks or maker’s name. These markings will also vary according to torch
type, age and place of manufacture, and the end user. A makers name is usually heavily stamped on the outside of the torch casing, often
in association with several other markings. These can include acceptance and inspection marks, proof marks, stores numbers, Admiralty
Pattern (A.P.) number and NATO Stock Number (N-S-N). There may also be instructions stamped on other external parts of a torch.

If the well-known broad arrow or crow’s foot mark (↑) is present, this usually indicates government (MOD) ownership of the item (fig.12).

An ‘Admiralty Pattern’ (A.P.) refers to a design specification for the manufacture of an item that is specified by the Admiralty. AP numbers were
used to identify a particular item and for naval stores use. Before NATO stock coding became more widely used, earlier MOD torches often have a simple.

Four digit group of AP numbers such as AP4456

And AP8965

On standard four-prong torches, the AP number is often stamped on the torch casing, or at one or both ends (on the metal lens rim and end cap; fig.6).

The two more recent torch designs with sliding top switches (figs.16&18) have a longer AP number
with a second series of numbers linked to the first  group (e.g. A.P. No.0563/20297;figs 20 & 21).

Fig 16

Fig 18

 

Fig 20

Fig 21

The 13-digit, numerical code of a NATO stock number is now used by all treaty countries to identify a standardized item which is
deemed as ‘stock listed’. On torches, the N-S-N is given as a ‘REF No’. For torch collectors, the 5th & 6th paired numbers
of the N-S-N sequence (called the 2-digit NCB) refers to the country of manufacture. For the UK the number is -99-.

All types of torches are well made from high quality brass (probably Admiralty or Naval qualities) and most were electroplated
(mainly chrome plated) for added protection against corrosion. Today, many torches are found with the worn chrome coating removed,
and the brass surfaces polished to a high shine for the sake of appearance. However, this is not how they were originally finished.

The rugged, simple construction of the different types of Siebe Gorman torches enables them to operate within the depth parameters of most
normal diving. All torches are powered by three ‘D-size’, 1.5 volt dry cell batteries. It was suggested in the Davis Manual that torches should not
be switched on until underwater, to prevent cracking of the glass lens by the cold water. Torch models with a glass ‘bullseye’ lens gives relatively
good illumination for close work (good in poor underwater visibility) but the beam is short on distance. In the more recent torch designs
(fig16.) the traditional glass lens was superseded with a flat, 3/8 inch thick acrylic lens, which throws a brighter, longer beam.

Fig 16

Type 1 Torch: ‘Switch’.

(Siebe Gorman D5 catalogue Photo No. 296a; Code Word: ‘TOCHA’): Approx. dates of manufacture 1935-55; weight 1.2 kg; length 32cm.
The barrel carries the inscription: SIEBE.GORMAN & Co Ltd  MAKERS  LONDON PATENDED A.P.8965 (fig.10). There are no other marks.

Figure 2 & 3 show this complete and disassembled torch.

Fig 2

Fig 3

This torch has a characteristic large octagonal nut to secure the lens. The battery tube of this design is accessed by unscrewing the
back switch assembly. However, the inside of all other torch designs are accessed from the front end by unscrewing the metal
lens protector, and removing the lamp reflector. Both ends of this old design are sealed using round, flat ‘gasket’ washers. The sealing
method was improved in later diving torches by using an ‘O’-ring seal in a groove. The switch mechanism of this older style is not the most
reliable, but even so, some of these torches were being reconditioned some 10 years after manufacture, as shown by the ‘Reconditioning Label’.

This torch normally came without a wrist-strap, but could be fitted by the manufacturer if desired.

Type 2 Torch: ‘Switchless’ standard (fig.4).

(Siebe Gorman D5 catalogue Photo No. 296b; Code Word ‘TOCBE’) Approximate dates of manufacture
1935-60 (2-prong type); 1961-94 (4-prong type). Torch weight 1.3 kg.; length: 28.0 to 28.5cm.

This is the most commonly encountered torch. It comes with a chrome leather wrist-strap which is sewn on (with older torches),
or attached by a copper or brass rivet.  The earlier variant of this torch has two metal ‘prongs’ to protect the glass lens.

The more recent version has 4 prongs, which gives better lens protection and easier storage, (the torch can stand upright). Figure 5 shows the torch parts.

This torch is switched on by fully screwing tight the metal lens protector assembly. The torch remains ‘on’ throughout a
dive, and in any position. If the light goes out when the torch is inverted, the coil compression spring at the bottom of the battery
tube is faulty, and needs stretching to give a good electrical contact. Many modern scuba diving torches use an ‘O’-ring seal
and simple screw lens housings to switch the torch on and off; a method pioneered by the Siebe Gorman torches.

The casing of a 4-prong torch normally carries the maker’s inscription which can vary.
Early 4-prong torches for navy use often have the maker’s inscription: SIEBE GORMAN & Co. Ltd MAKERS LONDON.

Stamped directly underneath this may be a ‘navy stores reference number’ (e.g. REF.  No Y3/WB/3159 and crows foot symbol;)

The maker’s name of SIEBE GORMAN may sometimes be stamped on the back end cap of the torch in
addition to the casing. The associated AP number (AP4456) may also be found on the metal lens rim (fig.6).

On more recent torches of this type, the AP number is often missing and is replaced with
the NATO Stock Number (N-S-N). This is given as ‘REF No 6230-99-942-7885’ (fig.13).

If the N-S reference number is not stamped on the torch casing under the maker’s inscription, it may
instead be stamped on a brass tag which is fastened to the leather wrist-strap with two rivets (fig.9).

The last 4-prong torches produced by Siebe Gorman at their Welsh factory (post 1975) have a full casing stamped address and
N-S number which reads: SIEBE GORMAN & Co Ltd AVONDALE WAY CWMBRAN, GWENT. REF.No. 6230-99-942-7885 (fig.14).

Another maker of the 4-prong torch is CEAG Ltd, which still produces lighting equipment for civilian and military uses. Their casing inscription
reads: CEAG LTD BARNSLEY & LONDON and the AP number is stamped on both the metal lens rim and end cap of the torch (fig.15).

Minor variations of torch part can be seen in lens caps, hand grips and casing seals. The inner locking ring of
the metal lens protector may carry the instructions: NOT TO BE REMOVED REPLACE LAMP FROM BACK.

Designs of hand grips can vary from being slightly flattened, thicker or having chamfer edges.

Waterproof seals can be of the flat washer type, or ‘O’-ring seal.

Designs with the an efficient ‘O’-ring seal will be more reliable as water resistant diving torches, whereas
washer sealed torches may have been produced for naval ‘topside use and damage control aboard ship’.

Some genuine and original 4-prong torches carry no makers name or markings at all, and these may have been produced for the
civilian market. However, copies of the 4-prong torch are still being made, are easily available, and have no markings or makers name.

Type 3 Torch: ‘Slide switch’.(fig16)

Date of manufacture 1964; weight 1.6 kg; length: 27.5cm. The casing has the maker’s name: SIEBE HEINKE OF ENGLAND.

This torch has a characteristic narrow metal lens protector, and is the predecessor of the wider version that followed a few years later.
Stamped betweenthe first knurled casing grip is: A.P.NO.0563/202927 with the date ‘1964’ underneath. Instead of a leather wrist-strap, there is a
lanyard hole on a curved metal plate on the end of the torch. Stamped into this plate may be several naval acceptance or inspector’s marks.

The torch has a circular, ring-type rubber seal which is unusually attached to the lamp reflector rim. The seal also isolates
the electrical circuit until the slide switch pushes a metal contactor against the reflector casing to complete the circuit.
Batteries are housed in an internal aluminium sleeve with a straight coil compression spring at the end (fig.19).

Type 4 Torch: ‘Slide switch’ (fig.18).

Dates of manufacture: 1967-1969; weight 2.0 kg; length 27.5cm. This torch supersedes the previous design and
improves on it. A large separate ‘O’-ring seals the lens housing; batteries are isolated in a grey painted and
non-conductive inner metal tube, and there is a strong, conical compression spring at the end of the battery housing (fig.19).

There are two variations of this design with different case markings. The first variant has the maker’s name: SIEBE HEINKE OF ENGLAND, and
stamped between the first casing grip is: A.P.NO.0563/202927 with the date ‘1969’ underneath. Between the second grip is the NATO
reference: N.S.N.6230-99-520-1611. Noticeably, the’9’ of 1969 over-stamps a ‘7’; 1967 being the probable year of manufacture (figs.20&21).

Fig 20

Fig 21

In 1968, the maker reverted to their original name with the inscription: SIEBE GORMAN. The AP number has been dropped in preference
for the NATO reference number. Stamped between the first grip is: NSN.6230.99-520-1611 with the date ‘1968’ underneath it.

It is likely there are other variations of these torch designs, and hopefully further information will be added to expand the information.

With Special thanks to Dr Mike Burchett for all the research which went into this article

• Last edited 16th January 2012