Grampound Patrol

A.K.A. (nickname)
The Grampound Bombers

Grampound is a village in Cornwall, England. It is at an ancient crossing point of the River Fal and today is on the A390 road six miles west of St Austell and eight miles east of Truro.

Patrol members
Name Occupation Posted from Until
Sergeant William John Knowles


06 Jan 1941 03 Dec 1944
Private Ira Edward E. Broom


25 Aug 1940 03 Dec 1944
Private Harold George Cock

Market gardener

15 Jun 1940 03 Dec 1944
Private Sidney Alfred Honey

Driver for timber merchant

06 Jan 1941 03 Dec 1944
Private Clement Arthur Knowles


06 Jan 1941 03 Dec 1944
Private William Montague John Osborne

Horseman and coal merchant

06 Sep 1942 03 Dec 1944
Private William John Richards

Thrashing machine owner

21 Nov 1942 03 Dec 1944
Operational Base (OB)

The OB and nearby possible OP were located in Trewithen, locally known as Barteliver Woods. The wood was part of the vast estate of Trewithen House and worked by the James' at Barteliver Farm where the Knowles worked all their lives. It is close to Old Hill where many of the Patrol lived and only a short walk down the riverside from Fore Street.

It is thought the main body of the OB was removed and sections of it used around Barteliver Farm by the Knowles brothers. There are two sheets of corrugated iron by the depression which is all that remains of the OB.

The OB was built by the Patrol and consisted of two chambers with an escape tunnel running north, exiting further down the slope of the hill near to a small stream running east to west which joins the River Fal at the bottom of the valley.

Constructed in the woodland, the OB was about 60 foot from the edge of the boundary bank. The site is near the top of a steep wooded slope, up from the stream.

The depression in the ground where the OB would have been is still visible. The deeper area is where the escape tunnel exited from. There are two sheets of corrugated iron by the depression.

The deepest part of the depression is about 16 foot by 10 foot but the shallow part of the depression extends another 25 to 30 foot by approximately 10 foot. It is difficult to tell how much of the depression was the base.

The depression runs east-west with the most likely spot for the entrance being at the eastern end.

The Observation Post is a much smaller site and has two sheets of corrugated iron lying in situ with a third lying out on the ground. We consider this could have been the observational post as from the edge of the woodland you had a view across the field down onto the village. You would have been able to monitor traffic on the A390 from the edge of the woodland.

This structure was around 6 foot by 4 foot and built into the side of a existing raised earthworks. It was around 60 foot uphill from the OB.

Patrol & OB pictures
OB Image
Caption & credit
Left to right : Jack Richards, Harold Cock, Cpl Sidney Honey, William Osbourne, Sgt William Knowles, Clem Knowles and Ire Broom (from Joy nee Knowles)
OB Image
Caption & credit
Grampound OB 2016
OB Image
Caption & credit
Looking down on Grampound OB escape tunnel running downhill
OB Image
Caption & credit
Two chambers of Grampound OB
OB Image
Caption & credit
Looking down on Grampound OB
OB Image
Caption & credit
View from OP showing main road on the hill
OB Image
Caption & credit
OP site
OB Image
Caption & credit
Remains near OP
OB Image
Caption & credit
Grampound OP 2016
OB Image
Caption & credit
Knowles home on Old Hill where explosives were delivered
OB Image
Caption & credit
Target of bridge on A390 in Grampound close to OB
OB Image
Caption & credit
Rifle range at Pomeroy Wood
OB Status
Collapsed with some visible remains
OB accessibility
The OB site is publicly accessible

Grampound Patrol

Patrol Targets

Grampound stands on the A390 which was, and is, a major route between Truro and Tavistock. Grampound Bridge is a bridging point over the River Fal which one assumes would have had strategic importance. Damage to this bridge would hamper a major supply route east, out of Cornwall. The main road could be easily seen from the OP.

One of the exercise targets for the Patrol was the RAF airfield at Portreath (Nancekuke) on the North Cornwall coast. This YouTube link shows the scale of the site and shows how impressive it was that seven “civilians” were able to break through the perimeter fence at night and “chalk-up” the tails of all the standing aircraft without being discovered. Both Probus and Grampound Patrols tested this target at different times and both were successful even after security was increased after the first raid.

Another night target was the RAF Radar Station at nearby Jacka Point, Portloe.


Grampound Patrol, along with Probus and Philleigh Patrols built and used a rifle range in the nearby Pomery Woods about a mile and a half from Probus village. Two firing points were built at the southern edge of the woods with the butts 400 yards across the valley of the River Fal. The butts were built by digging a hole and throwing the soil above to create a protective bank. It is remembered these were linked by a field telephone.

Training took place with Probus and Philleigh Patrols at Porthpean House, Porthpean with the Cornwall Scout Section.

Weapons and Equipment

It is assumed the Patrol had access to the standard arms and explosives.

Army lorries would often arrive outside the Knowles' house in Old Hill. They always arrived in the late evening, just as the light was failing. Boxes were carried around the back and stacked neatly in the shed at the end of the back garden. The shed was always firmly locked and the children told to keep away.

Will and Clem Knowles were brothers and next door neighbours on Old Hill with Ira Broom two doors down. The explosives stored in the garden shed of Will's house would have been easily accessible to all the Patrol.

Other information

Grampound and Probus were originally one Patrol that, with new recruits in both, split into two separate Patrols.

On V.E day the Probus and Grampound Patrols treated the locals to a “firework display”. Nobody was quite sure who set off the thunderflashes near the recreational ground in celebration.

The Patrol called themselves The Grampound Bombers.


Alwyn Harvey and his research for Defence of Britain Project.

Pat and Joy (nee Knowles) Champion

TNA reference WO199/3391

Hancock data held at B.R.A

Located and recorded by Philip Hadley.

Research by Philip Hadley along with Tina Tyler and Peter Wootton and Ryan Davies

Various newspapers and 1939 Register