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By Philip L. Armitage
Among the many World War 2 military artefacts recovered during archaeological
investigations on Berry Head carried out by Brixham Heritage Museum and Exeter
Archaeology are four base closing plugs from Mills No.36 hand grenades. Three of these
(Figure 1) were recovered during a metal detector survey of Berry Head Common by
members of Brixham Heritage Museum’s Field Research Team in 2003. The fourth example
(Figure 2) came to light during the 2009 archaeological excavations in Fort no. 1 at Berry
Head, supervised by Andrew Passmore of Exeter Archaeology (Passmore 2010: 10 - 12).
Description & identification
When first discovered, the three metal (copper alloy) objects from Berry Head Common were
not immediately recognised and although dated to the WW2 period were believed to be
simply the screw caps off petrol cans! However after inspection by Mr. Edgar Lawrance
(Master Gunner Royal Artillery, retired) they were all identified as the base closing plugs to
WW2 Mills No. 36M grenades. Although of the same design, each plug had been the product
of three different manufacturers, as evidenced by letters on the base (see Figure 1). Following
a lead suggested by Mr. Andrew Smith (editor of CBA SW Journal) who had located a
website specifically on grenade base plugs, the author contacted the website creator Mr.
David Sampson (an avid collector of grenade base plugs) who kindly provided information
on two of the three manufacturers represented (Sampson, pers. comm., 2008):
P.S.C. denotes the Parkinson Stone Company, whilst Q indicates the maker was the Qualcast
Company, Derby. Unfortunately the identity of the third manufacturer WML remains
Further research revealed that the Qualcast foundry in Derby had been established in 1920
and before WW2 produced lawnmowers. During the war the company’s workshops in Derby
were re-equipped to turn out mortar bombs and grenades. Within four months of the ending
of hostilities, in 1945, Qualcast had returned to normal operations and become the largest
manufacturer of lawnmowers at that time in the UK.
The more recently (2009) discovered base plug was probably manufactured by K. A. Kenrick
and Sons, West Bromwich.
Using the grenade
Fusing (arming) procedure
The base plug was an important component of the Mills 36M grenade when armed ready for
use, as described below.
As a safety measure, the igniter assembly of the grenade (consisting of a firing cap
surmounting a five-second safety fuse linked to a fulminate of mercury detonator) was
stored/transported separately from the main body of the grenade, which contained the
bursting charge. When the grenade was required to be armed, the igniter assembly was
inserted into the body and tightly secured in place by the base plug, as shown in Figure 1.

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Delivering of the grenade to the target
Once armed, the grenade was ready for use and subsequently could either be hand-thrown at
the enemy or “fired” from an adapted (ordinary) .303 calibre Lee-Enfield rifle, which
functioned as a short-range (up to 70 yards) mortar. The adapted rifle (known as the “E-Y
rifle”) was equipped with a cup discharger at the muzzle and the grenade fitted with a gas
check plate at its base (see Figure 1). Before inserting the grenade into the cup discharger, the
ringed split pin would be withdrawn and the striker leaver held firmly against the body of the
grenade. After leaving the cup discharger on the rifle (when fired), the striker leaver flew off,
allowing the spring-powered striker-rod to initiate the detonation sequence by descending
rapidly and impacting the firing cap, which ignited the safety fuse. The fuse burnt for five
seconds and then, in turn, set off the detonator/bursting charge.
Interpretation & Discussion
Of the three base plugs found on the Berry Head Common, two (accession numbers 6584.1 &
6584.2) appear to have been from unexploded grenades, whilst the third (accession number
6584.3) exhibits evidence of deriving from a detonated grenade - apparently therefore
indicating firing practice had been carried out at Berry Head. If this firing practice had taken
place somewhere on the Common it is unclear exactly who would have been involved as
there is no record of the local Home Guard training anywhere at Berry Head (see Armitage
2008). It is known however from a first-hand account (Coleman 2003) that the Brixham
Home Guard in late 1940 had practised using the E-Y rifle at Sharkham Point just around the
coast from Berry Head. Mr. Coleman in his account illustrates the inherent danger of using
such a weapon – he relates how one of the E-Y rifles “must have had a duff charge as the
grenade just popped out of the discharger cup and fell to the ground in front of us. There was
pandemonium and everyone scattered – it was lucky that the grenade rolled down the slope
out of harm’s way and no one was hurt” (Ibid).
Philip Armitage wishes to thank the following people for their assistance in researching the
grenade bases: Andrew Smith (Editor of CBA SW Journal), Edgar Lawrance (Brixham
Heritage Museum) and Dave Sampson. Sincere thanks also go to Robert Rouse for the very
fine drawings, and to the three metal detectorists who carried out the survey of the Berry
Head Common –John Britten, Otto Schneider and the late Doug Oseland. Thanks are also due
to Andrew Passmore (Site Supervisor, Exeter Archaeology) and volunteer excavation team
members from Berry Head Nature Reserve (Torbay Coast & Countryside Trust) and Brixham
Heritage Museum, who carried out the excavations in Fort no. 1.
Armitage, P. L. 2008 A “lost” WW2 Bofors anti-aircraft gun-position at Berry Head
Brixham. CBA South-west Journal No. 21 – June, AD 2008: 16 – 22.
Coleman, R. 2003 Brixham Battery Heritage Centre Group Newsletter October 2003.
Passmore, A. J. 2010 Archaeological Recording at Berry Head Brixham, Devon, May to
October 2009. Exeter Archaeology Report No. 10.73.
Sampson, D. 2008 website:

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Figure 1: Diagram showing the internal components of a WW2 Mills No. 36M grenade
together with the three base plugs found on Berry Head Common: Brixham Heritage
Museum Accession Numbers (right to left) 6584.1, 6584.2 & 6584.3. Drawings by Robert
Rouse, Brixham Heritage Museum.
Figure 2: Drawing of the base closing plug from Fort no. 1 Berry Head. Excavation site
EA8838 context 1115 small find no. 11. Drawing by Robert Rouse, Brixham Heritage

Figure 1

Figure 2