New Mills No 23

**Millsman** · 19th August 2012, 11:45 AM

Hi Mike. It's a standard Aluminium centrepiece. It's also got the only unissued convex lever I've got. I'm pretty sure nothing has ever been changed on it.

John

**siegfreid** · 19th August 2012, 01:54 PM

John . Impressive ! Norman may be able to add some details but I'm pretty sure D&B were involved with experimental Mills & an undated plug of that type may have more to it than meets the eye .Superb find . Mike.

**Millsman** · 19th August 2012, 02:16 PM

Originally Posted by siegfreid

John . Impressive ! Norman may be able to add some details but I'm pretty sure D&B were involved with experimental Mills & an undated plug of that type may have more to it than meets the eye .Superb find . Mike.

Hi Mike. It's one definately staying in my collection. I can't fault it really. The material the plug's made of is interesting. It could be grey iron as cast but may be an alloy. It looks a bit light for just iron.

John

**Bonnex** · 19th August 2012, 02:30 PM

John & Mike,

Exceptionally unusual especially since it is of the D&B embossed type. Hearn devised this plug design in about October 1916 and his company in Luton made a batch (500 I think) for shipment to J Allen Senior & Sons Ltd at their Twickenham works; plugs are marked JAS 10 16 No23 M I. As afar as I am aware this is the first notification of a D&B 23 MI plug of the Hearn style.

Tom and I corresponded about these a while back and hopefull he will pick up on this since my memory is pretty bad nowadays.

**Snufkin** · 19th August 2012, 06:42 PM

In July 1916 Trench Warfare Dept requested approval for the use of cast iron instead of steel for Mills base plugs. In September 1916 TWD met a representative of Messrs Dobson & Barlow to discuss the manufacture of plugs in CI, and both the firms of Dobson & Barlow, Bolton, and Brown & Green, Luton, were invited to submit samples.

The D&B samples were made from machined, malleable CI (basically heat treated white CI) bar, which was not what was required - cast plugs were the requirement. For interest, attached is a scan of the letter from D&B to TWD that accompanied the first machined-from-bar samples.

Brown & Green (for whom Hearn worked) produced 500 samples of a two-winged design, of which some went to James Allen Senior in Twickenham, and were marked with the latter's monogram. Hearn took out a patent on the plug design and the rest is history regarding the No.23 MkII and MkIII base plugs.

John's plug is likely a revised sample version based on the successful B&G submission, before large scale manufacture kicked in. Very quickly other contractors produced the Hearn design plug, and also Brown and Green "executed large orders as sub-contractors for other firms".

Tom

**Bonnex** · 19th August 2012, 08:20 PM

Many thanks Tom and apologies for not remembering the detail. Herewith an 11/16 dated one. 10/16 exists also.

.No23 M I (Hearn).jpg

**siegfreid** · 19th August 2012, 08:35 PM

Norman . Were those Hearn No23 Mk1 type plugs the ones fitted to the mini Mills ?

**Darrol** · 19th August 2012, 08:43 PM

the two samples that was submited . .was one of them brass?
Darrol.

**Snufkin** · 19th August 2012, 09:13 PM

Originally Posted by Darrol

the two samples that was submited . .was one of them brass?
Darrol.

Cast iron samples were asked for, as the idea of TWD was to reduce both cost of the base plugs, and consumption of brass. Had either B&G or D&B supplied a brass sample, TWD might have been a tad irritated.

Originally Posted by siegfreid

Norman . Were those Hearn No23 Mk1 type plugs the ones fitted to the mini Mills ?

Mike,

I have somewhere a photo of a mini Mills held by the RE museum, Chatham, totally stripped of its components and including a launching rod. It indeed had a No.23 MkI cast iron Hearn plug dated 10/16 (or maybe 11/16).

Tom.