Oldham & Son Ltd; Denton Manchester: Searchlight (Lead Acid Battery) Type TT Safety Lamp (very rare)

A truly magnificent blast from the past

By Dorian Stonehouse

Searchlight kindly loaned by Malcolm Rees, the Bridgend Inn (the Bridge) Brynamman.

THIS has to be one of the heaviest lamps I have ever repaired.  Although, it is a bane to carry over any distance, it will be running when all the plastic lamps have long since vanished from the face of the Earth.

This lamp is very heavy ! 

It is a stonking great lamp (torch/flash-light), weighing in at 5 Kilograms, with no acid in the batteries; thus making it one of the heaviest searchlight lamps I have ever handled!

Men were men in those

bygone days lad!

Oldham & Son Ltd; Denton, Manchester: Searchlight (Lead Acid Battery) Type TT Safety Lamp (very rare)

A great piece of Manchester history

 

Oldham & Son Ltd; Denton, Manchester: Searchlight (Lead Acid Battery) Type TT Safety Lamp (very rare)

Size really is everything

The lamp has a large 4 volt, low power/high power bulb

 

The reason for calling it a type TT lamp soon becomes apparent, as it has two type T lead acid cells, fused together at the hip⇑⇑ and are attached to the lamp metal housing; thereby keeping everything together.

The bolts came off easy – for a change!

Oldham & Son Ltd; Denton, Manchester: Searchlight (Lead Acid Battery) Type TT Safety Lamp (very rare)

Removing the back-plate is done by unscrewing the two spanner slotted tamper-proof bolts, which fit into a ridge, which runs along the back-end of the batteries ⇑⇑.

The bonnet just hinges off

Sometimes simple is best, as the battery is easily accessed once that bonnet is removed.

Was this really my lucky day? With the bonnet hanging down the side of the batteries⇑⇑, I proceeded to check the switch and bulb continuity; and to my astonishment, both seemed to be fully functioning.

Who hit that switch?

Oldham & Son Ltd; Denton, Manchester: Searchlight (Lead Acid Battery) Type TT Safety Lamp (very rare)

Now for that 2 x 4 volt model T lead- acid battery

The two cells are connected in parallel, giving 4 volts out to a lovely big 4 volt bulb.

The Oldham Type T cells looked completely dried out.   However, the write-up on these batteries is very interesting and worth checking out:  

http://www.pmp-docs.co.uk/Equipment%20User%20Manuals/

Battery charging port, as used in the mine cap-lamp room

Basically, Oldham explains in the instruction/service manual that their cap-lamp cells contain very little visible electrolyte, due to the presence of acid-absorbent material interspersed between the lead plates.

For this reason, the cells should only require periodic topping up with distilled water.   This makes perfect sense, as the last thing a miner wants, is a hazardous situation made worse by acid electrolyte spillage!

I had nothing to lose and so proceeded to fill up the cells with distilled water, and left the battery on charge for 8 hours.

By the way, the filler holes are located on the flat side of each cell⇑⇑ (not at the top, as one might expect).

Mission accomplished

(High beam)

Oldham & Son Ltd; Denton, Manchester: Searchlight (Lead Acid Battery) Type TT Safety Lamp (very rare)

Low beam

I hope you enjoyed reading my story, as much as I enjoyed getting this old beautiful lamp back to life!

P.S.

Please may I ask all visitors to post links on their social media accounts directing visitors to electrosparkles.com so that more people can enjoy the website, and join in to present their technical ideas for featuring.

Heartfelt thanks

Dorian.