Surface Sites - 'Q' Decoy Site

 Created 16-03-2002    Last update 23-09-2004

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Appeal For Information - 05/01/2019

I recognise a kindred spirit as I am researching the Downside Starfish at Bristol – we have recently purchased part of the site and any plans for it have gone on hold when we discovered that the big holes were bomb craters and that there is a piece of secret history complete with bunker, Z rocket emplacements and intact oil fire decoys, totally overgrown but all as they were left at the end of the war. Sadly much of this is on other people’s land but we do own a very small section of the ‘real thing’.

Does anyone have any photographs or information about the circular oil decoy fires used in the Starfish project ? There is good information available about the basket, grid and tank fed fires of the types used at Downside but there are also a series of 30 foot diameter earth banks, with a small sluice valve in each one and I can find nothing about how they worked. One of our local residents recalls playing in the detritus inside the mound and getting fearfully scolded by Mother for being plastered in black oil, but I can find almost nothing about the type of decoy. Logic says they were to simulate burning oil tanks and there is one brief mention of circular and crescent oil decoys, but that is all I can find. Any help would be appreciated!

Contact: Ross Floyd -



UK History & Description of the  'Q' Decoy Sites

   In the autumn of 1940, the mass bombing of Britain's cities - and in particular the devastation wrought on Coventry - turned the attention of Colonel J F Turner's Air Ministry department to the possibility of providing decoys to divert the bombers away from large urban targets. What was needed was the replication, as far as was possible, of a city under incendiary attack. It needed fires on a truly legendary scale. And thus was born the fabled Starfish site, the largest, most sophisticated decoy built in the war.
   Within days of the raid on Coventry on the night of 14/15 November, work started on the construction of these huge fire-based decoys around Britain's major towns and cities. From Southampton to Glasgow, from Birmingham to Crewe, tons of wood, and indeed anything combustible, was gathered to make improvised bonfires to try and draw some of the bombers away from the centres of population. But although immediately successful in some places, notably Bristol, Derby and Sheffield, these makeshift fire arrangements needed to be improved to guarantee a long-lasting effect with different kinds of fire to give a realistic variety of colour and intensity. If the Luftwaffe bomber pilots were to be deceived into thinking they were attacking a blazing town, the effects needed to be dramatic, varied and sustainable.
   Tests and experiments followed. Using steel tanks, troughs, pipes and grids, fuel could be made to pour, spray or trickle at timed intervals. Different kinds of flammable materials, variously soaked with boiling oil, paraffin or creosote, could create the random fire effects of burning houses, factories and power stations. Finally, four kinds of fire source which could be "manufactured" were decided upon, and construction work began.
   The Boiler Fire periodically released oil from a storage tank into a steel tray. This was heated by a 10 cwt coal fire which boiled the oil to such a tremendous temperature that it vaporised. When, every now and again, a gush of water was dropped into the tray, the effect was instantaneous and violent with huge flashes of white hot flame leaping up to 40 feet into the air. Storage tanks containing 480 gallons of oil and 200 gallons of water, could keep this dazzling display going for four hours. Some measure of the size of a Starfish site can be gained from the fact that a typical site could contain 12 - 14 Boiler Fires.
   The Grid Fire used paraffin as its base. This was continuously sprinkled onto a hot metal grid to which was attached wire waste and metal turnings. This burned with a steady yellow flame and although not as startling as the Boiler Fire, it introduced the essential element of variety.
   Basket Fires were the mainstay of Starfish sites. They came as a 21/2 cwt package of inflammable materials, boxed into a wooden crate measuring 3' x 2' x 2'. Soaked with creosote, these blocks were arranged in irregular groups of up to 24, sometimes even more.
   Coal fires were exactly what their name implies, but on a grand scale. A double brazier, twenty feet long, held 4 cwt of creosoted firewood and three tons of lump coal, giving off an enormous deep red glow. A variation of this fed diesel oil onto the burning coals through a sprinkler pipe.
   A normal Starfish site could get through 25 tons of fuel in four hours. A few had double this capacity. In common with the lighting decoys and the "QF" sites, the Starfish displays were ignited electrically from a control bunker about 600 yards away. This was heavily built of concrete but, to be on the safe side, it was banked around with earth. Nevertheless, with bombs dropping so close, no doubt the decoy controllers kept their fingers crossed for the bomb-aiming skills of the German airmen.
   By June 1944, decoy sites had been attacked on 730 occasions. Each of these ranged from a single night-time bomber dropping its load onto a "Q" decoy site to the mass attacks on Starfish sites. In drawing the high explosives and incendiaries on to themselves, they were undoubtedly responsible for saving the lives of thousands of people.


Portsmouth's 'Q' Decoy Site

To help protect Portsmouth from German night bombing, a series of 'Q' decoy sites were built in Langstone Harbour and on Sinah Common Hayling Island. These elaborate constructions consisted of two main elements. Firstly a string of carefully positioned structures were erected, mainly in the north of the harbour, which when lit from the inside would mimic the effect of light shining through chinks in doors and windows in a carelessly blacked out area. The second, and most crucial element of the deception plan was the deployment of decoy fires known as "Starfish" sites. These decoys were designed to present to the enemy pilots a convincing illusion of a city under attack. 

This site was often dramatically successful; on the night of 17/18 April 1941, over 140 enemy aircraft were lured away and  un-loaded in excess of 200 air-dropped munitions, originally intended for the City of Portsmouth, into Langstone Harbour and Farlington Marshes. This was the most successful Q-site operation of the entire war.

Most of the fires were oil-fuelled and all were ignited from a central Starfish control point. The master control post was at Fort Purbrook, a Palmerston Fort located at the east of Portsdown (hence my interest). Sub-control points were also provided, most of which still exist.

During the period 1940 - 1944 Portsmouth suffered 67 air raids with the warning sirens sounding 1,581 times. The number of air dropped munitions were: 1,320 high explosive, 38,000 incendiaries and 38 parachute mines. 6,625 homes were destroyed with 74,435 damaged. 930 people were killed and 2,837 injured.


 Google Earth Aerial View

 Below is a map of the 'Q' decoy site set-up. This shows all of the elements that are known to have existed, though not necessarily all at once as the site was subject to many revisions. There were two distinct decoy sites occupying the same location. One was a Civilian Starfish (SF series - Portsmouth designation SF16) and the other was the Naval decoy (N series - Portsmouth designation N14). Some of the map references on documents at the National Archives are incorrect so these have been re-interpreted where necessary.

NEW 23-09-2004

Langstone Q Decoy map


SF = Starfish QL = Lights QF  = Fires
MC= Main Control CS= Control Shelter  
Map Code Location Type Civilian Code Naval Code


FP Fort Purbrook MC      SU678064
FC Farlington Control CS      SU680042
FC2 Farlington SF Control CS    


4C 40 Acre Farm Control CS      SU677043
HC Hayling Control CS      SU715023
SC Sinah Control CS    SZ694995
PO1 Farlington Marshes SF SF16a PO1 SU687041
PO2a North Binness Island QL   PO2 SU695046
PO2b 40 Acre Farm SF/QL    PO2 SU696035
PO3a Hayling Island - (W) SF/QF   PO3 SU715012
PO3b Long Island QL   PO3 SU702042
PO4a Sinah Common  SF SF16b PO4 SZ695992
PO4b Baker's Island QF   PO4 SU696035
PO5 South Binness Island QF   PO5 SU698033
PO6 Round Nap Island QF   PO6 SU705034
PO7 Old Oyster Beds QL   PO7 SU705033
PO8 Hayling Island - west SF/QF   PO8 SU717023
PO9 Sinah Sands QL   PO9 SU693009

The sites today

Langstone Harbour can be a pretty inhospitable place for any structure, and over the years all trace of the 'Q' lighting, fires and leaky lights have been removed or swept away. When I was very young, I remember seeing something on the Hayling sands (J in the above graphic) which looked just like a cut-away sea mine, and inside were lamp holders still containing electric bulbs. I now guess that this was a Naval armoured 'leaky light'. Below is a summary of the Control Shelters, QL, QF and Starfish sites today.

Map Code Location Condition (2004)
FP Fort Purbrook Fort exists. Control probably located
FC Farlington Control Still exists. Condition poor
FC2 Farlington SF Control Still exists. Condition fair
4C 40 Acre Farm Control Obliterated by A27(M) road works
HC Hayling Control Still exists. Partly demolished
SC Sinah Control Under investigation
PO1 Farlington Marshes No trace
PO2a North Binness Island Under investigation
PO2b 40 Acre Farm Obliterated by A27(M) road works
PO3a Hayling Island - (W) Under investigation
PO3b Long Island Under investigation
PO4a Sinah Common  No trace
PO4b Baker's Island Under investigation
PO5 South Binness Island Under investigation
PO6 Round Nap Island Under investigation
PO7 Old Oyster Beds Under investigation
PO8 Hayling Island - west Under investigation
PO9 Sinah Sands No trace
View from Fort Purbrook

 The view south east from the top of the Barrack Block inside Fort Purbrook, which was the Q decoy site main control centre. From here you can see the entire Q decoy site area: Farlington Marshes, Langstone Harbour, and Hayling Island. At the lower left of the photo is a structure thought to be the Q decoy site observation post.

Q site observation post

 This building on top of the eastern end of the Barrack Block at Fort Purbrook is thought to be part of the main Q decoy site control. There is evidence that another structure was built upon its roof which would have given a clear view over the crenellations.


 Q site - Farlington Control

 The Farlington Control No1. The rusty box is the observation hatch, looking out over Langstone Harbour. To the right is the entrance and blast wall. Some of the original earth covering on the roof still survives.  

Visit this site - Portsdown Walk No3

farlington control

 The Farlington Control No1 looking northeast. This shelter had its own electrical generator which was stripped out when the site was decommissioned in 1945.

farlington control inside

 The Farlington Control No1 on the inside. There were 3 distinct sections. The main room where this photo was taken, a smaller one right at the back, and 2 alcoves either side of the centre. It's not worth showing any more interior photos, as they're all pretty much trashed like this one.


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