Cyril Hilsum: Claribel radar

Cyril Hilsum recalls the development of Claribel bullet detecting radar used to find snipers in Northern Ireland.

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They approached us with a problem they had in Northern Ireland and they said they had a problem with snipers. That essentially people would fire at the troops, that either would be vehicles or individual soldiers, it was very difficult to locate the sniper. There’d be echoes of things, they would be on roof tops or firing from windows of the flats, anywhere. And he said, ‘We actually – you have no idea where they’re firing from,’ and said, ‘do you have any way of actually locating a sniper?’ And I said, ‘I think you ought to be able to do it by radar,’ and they said, ‘How can you do it by radar?’ I said, ‘Because if there’s one thing you can be certain of, that the bullet’s going to come pretty near you so it’s a target that’s very – at very short range and you ought to be able to differentiate because there isn’t much that’s travelling at the speed of a bullet, so you could have a system that is actually programmed to work for very fast objects very near you.’ And they said, ‘Hmm, but how are you going to do that?’ and I said, ‘Well I’m pretty certain we can use one of our miniature radar sets.’ So I took one of our small radars and I put it in the corridor and I found a motor and I put a – a bit of string on the end of the rotating thing and I put a ball bearing, you know, a little cage on it so it could whirl around. And I put this so there was the corridor and there was the motor flying thing - and there was the thing whirling around. I set up to do this and started the motor going, went down the other end to look at what was happening in my radar set, by the time I got there I was getting a little pip immediately coming, peep peep peep, I swung around and before I could start rejoicing the bloody ball bearing came off the string. It went straight through a door. But anyway when I came rushing up to find out where it – I found an astounded scientist who was muttering that this ball had started bouncing [laughs] around his lab and what the hell. Well there was an enquiry but I had proved my point and went on to prove my point that I could detect something the size of a ball bearing at 100 yards and it was fairly obvious that I’d be able to detect a bullet. And we – we developed a system, which essentially measured the position of the bullet, then you got the angle so you actually got the angle, you didn’t get the range, you got the angle, but that’s what they wanted, they wanted to know in which direction they were going to look. It was called Clarabel, it was developed in six months, made by Racal and the first models were put into Northern Ireland and sniping stopped. And we were really disappointed ‘cause we’d hoped to see some snipers being arrested and taken off in chains, but what actually happened was that once they realised that the soldiers knew where they were they didn’t like the idea that immediately the people would stop and start moving directly towards them, they could see that – they knew where they were.

  • Interviewee Cyril Hilsum
  • Duration 00:03:43
  • Copyright British Library Board
  • Interviewer Thomas Lean
  • Date of interview 4/12/2012
  • Shelfmark C1379/69

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