Bombing decoy and Z anti aircraft site

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Bishop

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Krela and myself had a look at an old WW2 bombing decoy site and Z anti aircraft battery back in January its down on the Mendips on the Black Down hills just to the north of Cheddar. Most of the pics were taken by Krela.

The bombing decoy was part of a sophisticated system aimed at diverting
hostile air attacks away from Bristol whilst at the same time drawing
enemy bombers to within range of anti-aircraft fire. In the event of an
imminent air raid on Bristol, lighting decoys were put into operation on
Black Down south of Burrington and in the vicinity of Ashridge Farm. The
lighting decoys, known as QL sites, attempted to simulate the city lights
of Bristol under black-out conditions and they included devices to mimic
the flickering lights of railway marshalling yards as seen from the air
and the characteristic arcing flash of city trams. If the decoy was
considered to have been successful in attracting aircraft then
pre-prepared fires (known as QF sites) were electrically ignited to create
the illusion of targets having been set alight. The QF sites were operated
from control buildings placed at least 400m from the decoy fires; two
control buildings survive

Above taken from an English Heritage scheduled monument PDF.

http://www.magic.gov.uk/rsm/33064.pdf

Below is an aerial shot of the decoy site taken by the RAF just after the war.
The decoy is a grid pattern with mounds which would have lights on them to
simulate streetlights, from what I've read it seems the decoy mounds were
originally anti aircraft/glider landing obstructions.



Black Down hills today aerial shot from Live Local.

http://maps.live.com/default.aspx?v=2&cp=51.310443~-2.743342&style=h&lvl=16&tilt=-90&dir=0&alt=-1000

Pit for burning of petrol to simulate bombed houses?



Bombing decoy command bunker, this would have originally been covered in earth for increased protection. Theres two of these bunkers left of identical design which consist of, the outer blast wall, corridor, two rooms of which one would have contained three electrical generators (for the lighting of the decoy). The other room would have contained switchgear, communications equipment and a stove.



My size 12's stood on one of the three electrical generator plinths.



The second decoy bunker is identical in design to the first but still has its covering of earth banking protection, its entrance is gated and padlocked.



Side view of the second bunker, blast wall and entrance to the left. Small brick/concrete hole straight ahead was probably for electrical cables to power the lighting decoy.



Ooh, ooh! Is that an interesting pillbox or another decoy command bunker?
Nope its a water or fuel tank, oh well.



On top of the water/fuel tank, looks like 1954 to me, not exactly WW2 but I guess someone could have converted the tank or recovered it? Could still be wartime and connected to the decoy site.



Behind the second decoy bunker is the top of the hill where the anti aircraft/glider landing obstructions are, loads of gorse and brambles and on the ground you can't really see much of the decoy, the aerial pic and link I posted above will give you a much better idea of the layout.



B
 

Bishop

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Slightly to the south of the bombing decoy site are the remains of a WW2 Z anti aircraft battery this was sited to fire at any German bombers that were lured to the decoy site (so drop your bombs on the hills instead of Bristol and have a rocket or 128 for your trouble, lol).

Now how do I explain the Z rocket batteries? I know I'll be a lazy sod and quote Krela.

These were short range rocket powered projectiles that were used to suppliment the AA gun batteries. Instead of barrel rifling they used fins to stabilise their flight, hence being unrotated.

They fired a 3" wide 38" long projectile which at the hight of its travel released a mine on a wire, the idea being that a plane would fly into the wire and draw the mine into itself. They weren't particularly accurate instead relying on sheer number of projectiles to work.

Z rocket projector with four rockets.



There various types of rocket projector that all seems to fire the same type of rocket, the most common projector fired two rockets and would be deployed in a battery of 64 projectors so when the order came to fire the battery would launch all 128 rockets. Its rather hard to find information about these rockets but I believe later in the war they were modified with a new type of fuse which made them much more effective, even though it looks like quite a skinny crappy rocket apparently they each had a blast radius of 70ft.

Z rocket projector concrete plinth.





Another Z rocket projector but of different design.



The field supposedly has numerous concrete plinths for the projectors of at least three different types, round, hexagonal and hexagonal with different markings. Now I was up for a good march around the field but as my luck would have it there was a blinking bull in the field, not the biggest or most fearsome of bulls in fact he looked quite young but I wasn't in the mood to take chances so I only snaped two of the plinths/bases.

Edge of a hexagonal projector base/plinth.




Young local.




Z rockets firing.





b
 

krela

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Nice write up boss.

The only thing I would add to it is that z-rocket was a pet name coined by the operators, their technical name was 'unrotated projectile' the explanation of which can be found where Bishop quotes me from another website above.

I'm not entirely sure why they were coined as z-rockets, I'll have to investigate that unless someone else can tell me :)

Also, just for the sake of technical accuracy and completeness, if I remember correctly the decoys were of the starfish variety, which means they were designed to emulate a burning residential area (in this case Bristol).
 

Foxylady

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What a superb find! That is really fascinating (never heard of these before) & I'm amazed that the projector bases are still there.
Cheers guys.
Foxy :)

P.S. I like the bull. That could have been one of those times when you find out if you can clear a five-bar gate! :lol:
 

Lightbuoy

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Yet another excellentay report B! :)
Was there access into those bunkers?
Amazing how crisp the numbering still is on those bases!
Thanks for the background info too -most interesting.

[QUOTE P.S. I like the bull. That could have been one of those times when you find out if you can clear a five-bar gate! :lol:[/QUOTE]

Hey, now that's got me thinking Foxy -how about making it an Olympic event (it's humane on the bulls, keeps both bull & athlete fit & healthy, and would be an option for any Farmer when it comes to diversification!!!):D

Lb:cool:
 

Foxylady

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Lightbuoy;10656; said:
Hey, now that's got me thinking Foxy -how about making it an Olympic event (it's humane on the bulls, keeps both bull & athlete fit & healthy, and would be an option for any Farmer when it comes to diversification!!!):D

Lol :lol:
That's brilliant. It could be an initiation rite for urban explorers, like the Ancient Minoans!!!
 

smileysal

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the pics and the history of the site are great, thank you for sharing. its amazing the numbers are all there and clearly seen. didn't know this place existed. well done for finding it.

and on the bull note, jeez, its huge! lmao. yep, sounds like the farmer could diversify with clearing a five bar gate for the london olympics :lol: like it lol.

:) Sal
 

Bishop

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Thanks for all the nice comments :)

Heres another pic of one of the 'Z' UP rocket projecter bases, pic is from the Somerset Historic Enviroment Record website, this base is different from the other two that I've photographed.



Details:

The well preserved remains of a rocket anti aircraft battery survive to the E of the bombing decoy control room (PRN 11466). They consist of a number of hexagonal concrete bases 8 feet across, some with circular cast iron bearing indicators around the edge. The others appear to have the bearings cast into the concrete. Each base has two irregular additional areas to either side. The bases and dwarf walls of two ammunition shelters survive in the field and the base of a third survives in the concrete animal yard. It is likely that a fourth was sited beneath the large (post war) Romney hut which may also have removed further launch pads. {1}

The rockets were controlled from the decoy site control room. {2}

Two of the projector bases were dug up in c2001 when a new barn was built. These were retained and have been replaced at the edge of the field. {3}

A condition survey identified 19 surviving bases mostly on a 14 yard grid (including the two removed ones). There may be another hidden under a dung heap. Eight have cast iron rings, seven with rings cast in the concrete using inverted cast iron rings, and 4 whose design is at present obscured. The two type appear to alternate. The cast iron rings are in eight pieces with a flange to bolt them together. A 1971 aerial photograph seems to show 23 bases which suggests that originally there would have been 24. {4}

Two further bases have been removed by the construction of another barn. {5}

Monument scheduled on 1 April 2003 together with decoy control room PRN 11466. {6}

Above quote (and pic) taken from page below.
http://webapp1.somerset.gov.uk/her/details.asp?prn=12835

So theres something like 17 bases remaining in this field? I think Krela and myself will have to go back here at some point, just hope the bull is in a different field, if its not then its Krela's turn to do the honours.

B :)
 

nizzer

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brilliant find. ther's jnust nowt up north. as for the bull, i'm sorry but you ain't swwn nuthin. spent a couple of years in oz and to be honest id've had him, and thirty cows and bullocks for breakfast. all you need is a good stock of wee stones, a big fuck off stick ( for confidence) and a very loud shouting voice and you'll be fine. For further stock related problems, i'm your man.....!:)
 

Bishop

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Mr Nizzer wrote.

brilliant find. ther's jnust nowt up north. as for the bull, i'm sorry but you ain't swwn nuthin. spent a couple of years in oz and to be honest id've had him, and thirty cows and bullocks for breakfast. all you need is a good stock of wee stones, a big fuck off stick ( for confidence) and a very loud shouting voice and you'll be fine. For further stock related problems, i'm your man.....!

I might live in the smoke but I spent a lot of summers on my great uncle's Cornish dairy farm, believe me the bull above is nothing he was only a sprog but I know for sure he could run faster than me and I didn't have the big f*ck off stick for confidence, just a very expensive camera and a desire not to get nutted by cattle.

B :neutral:
 

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