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Appeal for help from ex EOD personel - Forster

R

Rockteer

Well-Known Member
Hi,

I am part of an aviation group (as well as collecting and restoring air dropped weapons), we have a Forster bomb detector which works just as well when looking for engines of aircraft. I am wondering if anyone has any experience with these, how does one test the depth that it is detecting, is there a way of tuning them? It is a new piece of kit so am lacking confidence in it, if there was some way of testing it that would be great. One idea was to bury something like an old car engine at depth as a testing area but this is really not practical. If anyone can offer any advice please e-mail me.

Also please note this is not used to locate live ordnance although that is what it was designed to do originally, in fact we steer clear of such sites. I just thought that was worth pointing out in case anyone was wondering :xd:

Thanks
 
Hi rocketeer
You dont mention what version you have , but i guess its the 4021 which replaced the earlier types 4015 and 4016, the detection range of a 500 KG bomb is listed as 6 mtrs , this size i would think is about right for an aircraft engine?
 
Hi Steve,
What experience have you had using these locators, i have never used any type and would be interested to know, i know that Spotter uses one for work on a daily basis as i am sure most other EOC EOD personal do.
Best Weasel.
 
rockteer I actually work in munitions clearance and have done for several years,fuzemans text book reference of 6mtrs for a 500kg is correct, but there are other things you need to know about the locator that can affect the depth and strength of readings that can only be picked up by actual experience using them,like i said earlier ive sent you a PM and look forward to hearing from you.
spotter
 
Hi weasel
I have used one years ago on a course i attended , i still have the procedures for setting them up.
 
Locator

This may help you as the for both the calculations are the same
 

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4021 Locator;

sir:
I taught the 4021 at DEODS for two years and the U.s. Mk. 21 Mod 0 wwhich is almost the same.
There is really not any testing necessary that I am aware of. Use fresh batteries. the key in searching is to keep the tip of the locator at a constant height above the ground., about two to three inches.
take the locator to a known metal free area, zero the meter place a piece of ferris metal and just pass the search head over it to get a tone and a reading.
Small items will quickly disappear if you raise the head up off the ground. whereas a large item can be read over a much larger area. Use the half maximum reading shown in the last post to determine object's depth.
Boreholing is another method and requires some training and experience to use.
Configured as a borehole locator the 4021 can also be towed underwater.
I should think that an A/C engine, depending on its depth, would give you a very high and consistant reading over a six foot diameter area, falling off as you leave the centre of the object.
I have found that the half max formula can be accurate within 6 -10 inches if you are patient and take accurate readings and measurements between the two half max readings.
I have located 110 pound gas bombs at 9 feet depths.
Happy Hunting,
Regards,
John aka Bart
 
Hi, thanks to all for your replies, I have only just caught up with the post. I have the Ferex 4.012 model and also an older model.
 
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