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All You Ever Wanted To Know About The Bonklip Bracelet But Were Afraid To Ask

Ricky Lee
November 09, 2013 08:40AM

First, kudos to Corvus Watch Company, who have an excellent article on the Bonlklip bracelet on their blog (See HERE). Indeed, you will find the following treatise by Messrs. Meijden and Koenig linked there.

While the Corvus article is more comprehensive in some ways (And I highly encourage you to read it!), the Meijden-Koenig article focuses more specifically on the Bonklip as used by the RAF and, in particular, as fitted to my beloved Jaeger-LeCoultre Mk. XI. Anyway, here ye go...


THE BONKLIP BRACELET IN HIS MAJESTY’s SERVICE.

By : Adrian van der Meijden and Thomas Koenig

Introduction

In the past vintage military wrist watches often have been presented in mint condition of movement, case and dial, and they have been fitted with new, contemporary straps. But in the last few years the level of restoration has asked for increased authenticity, resulting in a disaffection towards overdone restorations as well as in interest in up to now disregarded details like watch straps.
Research on original issued watch straps is quite difficult as leather and straps made of fabric are subject to aging and substantial wear and tear. So, today they are either lost or in devastating condition. Furthermore, British Armed Forces paperwork is not very helpful as only few words are spent on straps. Even if an old watch has still a vintage strap it is not sure, whether this strap is an authentic issued one or just a fancy strap mounted by a later civilian owner.

From the List of Changes as far as ROYAL ARMY equipment is concerned and pertaining to the ROYAL AIR FORCE equipment from AP 1086, it is known that during WW II leather straps for both, wrist watches and pocket watches were predominant. In contrast, the American Armed Forces during WW II already introduced canvas and nylon straps for military service. But information on the exact colour, exact dimensions and the method to attach them to the fixed lugs of the watches is very scarce.

Other than on leather straps and straps made of fabric, the use of metal watch bracelets has been documented much better. The best known metal bracelet issued to the British Armed Forces is the so called BONKLIP. We will try to describe this specific bracelet, which for some twenty years was a standard bracelet for the ROYAL AIR FORCE and the FLEET AIR ARM.

History and patents

“BONKLIP” appears to be trade name, probably some kind of pun with the words “BON” and “CLIP”. A closer look on a BONKLIP bracelet reveals that it wears not only the brand name on its closure element, but also the inscription “MADE IN ENGLAND, B.H.B.& S, Pat. No. 349657”. (Fig.1,2)

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The aforementioned Patent No. leads to the inventor, DUDLEY RUSSEL HOWITT of 67 Hatton Garden, London. The patent has been applied for, on March 6, 1930 and it has been published on June 4, 1930. (Fig.3)

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The invention describes the patent specification as follows: “This invention relates to flexible metal wrist bands, bracelets, necklets and the like and has for its object to construct such class of article and its fastening means in an improved manner whereby the fastening can be effected easily and simply with one hand and is neat in appearance”.

Three years later HOWITT found his patent registered at the REICHSPATENTAMT in Germany under DRP No. 577586. (Fig.4)

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The German Patent application is an exact translation of the English one. The essence of HOWITTS invention is described in the English Patent Abstract GB 349657 (Fig.5) and in additional drawings (Fig.6)

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Use in the British Armed Forces

As the invention originally was made for jewellery and for improvement of the inferior closure systems of bracelets known of that era, it is no surprise that the British Armed Forces took no notice of this patent immediately.

But during WW II the Allied planes flew higher and higher, resulting in the need to provide warm clothing to the air crew members as the cockpit at that time lacked heating. That caused some inconvenience to the navigators: Their watches, 6B/159 Navigational Wristwatches, were worn on normal, short pigskin straps and therefore beneath the warm Irvin flight jackets. It took some time to uncover the watch and it was nearly impossible to handle the sextant for navigation and simultaneously record the exact time. There was an increasing demand for a strap, which length easily could be varied, allowing to wear the watch directly on the wrist, but also over the flight jacket.

This specification was met in 1949 when one of the most famous military watches, the Mk. 11, was introduced into RAF and FAA service. It was the first watch in the RAF fitted with a BONKLIP strap. (ref.1 ).

As with every item of RAF equipment, a Store Ref. No. was assigned, not only to the Mk. 11, i.e. 6B/346, but as well to the BONKLIP straps. As three different versions of the BONKLIP were in use with the RAF, three different Store Ref. Nos. were issued, namely 6B/2763 (17.5 mm in width designated to be used with the Mk. 11, 6B/3224 (19.0mm) and 6B/3033 (20.0 mm in width).

The last two to fit the chronograph 6B/551 H.S 9. and the Watch, Wrist, General Service 6B/9101000.

The size of the links of the strap is for all three aforementioned types of BONKLIPS the same. Only the end pieces vary in width according to the size of the lugs of the different watches. The 17.5 mm 6B/2763 was tailor made for the IWC Mk. 11 with 18 mm lugs, while for the Jaeger LeCoultre Mk. 11 having only 17.0 mm lugs, some material had to be filed off to make the end pieces fit.

There is no evidence that the ROYAL ARMY has ever used a BONKLIP strap. Probably the BONKLIP was never issued outside of the RAF and the FLEET AIR ARM. That would be plausible as except for diver’s watches there was no need within the ROYAL ARMY and ROYAL navy (except for the helicopter and plane pilots) to vary the width of the bracelet/watch strap during a mission. For diver’s watches BONKLIPS were not really suitable, because the watch was fastened more secure with a nylon “NATO” strap and because BONKLIPS could have corroded when steadily used in salty sea water. BONKLIPS mounted on 6B/159 Navigational Wristwatches and on Royal Army service watches probably are no authentic issued straps, but have been” upgraded” by their owners in a way.

In 1981 the MINISTRY OF DEFENCE issued the DEFENCE STANDARD 66-4(Part 5)/Issue 3, Watch, Wrist, Electronic, Navigator, Luminous and Non-Luminous. This Standard superseded the DEFENCE STANDARD of July 1973. The 1981 Standard declared that several items in his Majesty’s service were no longer cleared for issue. Among other military items, the last 4 surviving W.W.W. watches, namely IWC (listed as International), Omega, Record and Timor were taken out of service. Also IWC’s most famous military watch, the Mk. 11, and the mechanical wrist chronographs had to go. Together with the watches the BONKLIP bracelet was not provided anymore. Nylon and leather straps with the NATO stock number 6645-99-527-7059 were the replacements. (Fig.7)

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For what reason the BONKLIP had been the first choice in the Royal Air Force for such a long period?

Due to its unique closing system the BONKLIP could be used at different lengths, fitting on the bare wrist as well as over military clothing. Probably no other contemporary metal strap allowed to use every link present, as the one to put on the closing clip .In this way the BONKLIP was adjustable over a wide range, precise to a few millimetres. The nylon straps issued since 1954 allowed that variation as well, but here serious injuries in crash landings have been reported. In contact with fire, nylon melts and causes serious burning wounds of the wrist.

Where many collectors may be charmed by the appearance of a W.W.W. or a Mark 11, few consider a BONKLIP as a nice looking bracelet. Compared to the current sturdy metal straps it looks rather thin and puny. Many collectors therefore use the well known NATO strap or a leather one. In Z. WESELOWSKI’S book: “A concise guide to Military Timepieces 1880-1990”, only 2 wristwatches have been depicted with a metal strap, of which one may be a BONKLIP.(ref. 2 ) However, the BONKLIP bracelet served his Majesty for over 2 decades and this fact indicates that this tiny strap must have been able to fulfil a heavy duty. It is therefore that we have tried to elucidate the history of this peculiar product that has played a modest but obvious role in the British military watch history. (fig.8,9)

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Original article in PDF format is HERE



Hope ye enjoyed it!

Cheers!

-Ricky

Further reading:

The Untold History of the Bonklip Watch Bracelet by Corvus

‘Man is Not Lost’ an Account of the Mk 11 Navigational Wristwatch (PDF, on Corvus blog)

The Bonklip Bracelet in his Majesty's Service (PDF, on Corvus blog)

Ricky Lee McBroom
"A man, like a watch, is to be valued for his manner of going." - William Penn

Messages In This Thread

All You Ever Wanted To Know About The Bonklip Bracelet But Were Afraid To Ask Jpeg Attachments URL PDF Attachments

 Ricky Lee 698 April 08, 2012 09:37AM

Great info. Thanks Ricky.Thumbs up! (n/t)

 Mark C. 68 April 08, 2012 09:14PM

Hey...good show Ricky!!!
I have one currently, and "correctly" mounted on my west end watch I'll have to post some pics tomorrow!!!

 dano0 83 April 08, 2012 07:48PM

Re: I have one currently, and "correctly" mounted on my west end watch I'll have to post some pics tomorrow!!! Gif Attachments
cOOl! Cool
Since you promised photos I won't break out the Dreaded Icon...

Laughing Cheers!

 Ricky Lee 56 April 09, 2012 04:56AM

I would not mind finding one for my vintage West End someday. Jpeg Attachments
The bracelet was an actual factory option.

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But the pigskin also comes close to an original option too.

Photo by Chris L

 Chris L 73 April 08, 2012 08:39PM

Re: The bracelet was an actual factory option. Jpeg Attachments
I did not know that! Blushing

Thank you!

Not surprising, really, as it appears that a number of companies sold watches with Bonklips as OEM fitment. Even..

Quote
Corvus

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1940's Rolex sold recently at Christie's with apparently original Bonklip.
..Rolex, it would seem. Smile

Cheers!

 Ricky Lee 87 April 09, 2012 05:02AM

Wow! Cool topic, Ricky! Cheers!Thumbs up! (n/t)

 IF 55 April 08, 2012 12:27PM

I need me one o' them there bracelets...
Wink Cheers!

 Ricky Lee 66 April 08, 2012 02:53PM

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