‘The London weapon has been stopped in France, Prime Minister,’ Sir Michael Geraghty began, as he walked into the private office at number 10 Downing Street. ‘There were no casualties on our side, and the operation was entirely successful.’
‘Excellent news,’ the Prime Minister said, rubbing his hands and looking cheerful.
‘It isn’t all good news, unfortunately,’ Geraghty went on. He had been briefed by Simpson about Gibraltar only minutes earlier. ‘The architects of this scheme have arranged a demonstration of the weapon’s power in Gibraltar, and we are racing to disarm the device before it can be detonated.’
The Prime Minister sat down, and motioned Geraghty to a chair. ‘Explain, please.’
‘There is a Russian ship there, Prime Minister, called the
It was nearly nine thirty before the Aldermaston team finally completed the disarming of the weapon, and Dewar beckoned Richter over. ‘All done,’ he said. ‘Sorry it took so long, but we obviously didn’t want any accidents.’
‘Quite,’ Richter replied. ‘Will it take me as long with the Gibraltar weapon?’
Dewar shook his head firmly. ‘It shouldn’t do. Our main problem was not knowing how all the anti-tamper devices were rigged. You should be able to disable the other weapon in about ten minutes. Now, come with me and I’ll show you.’
They climbed into the back of the lorry and looked at the Russian bomb. It was much smaller than Richter had expected, and didn’t look like a bomb at all. The outer steel box was about ten feet long, four feet high and five wide. At one end of it were three large lead-acid batteries, wired in parallel, while the weapon itself was a virtually invisible three-foot-diameter cylinder underneath a tangle of wires and cables in the centre of the box.
‘Right,’ said Dewar. ‘The first thing is the bank of batteries. Do not under any circumstances disconnect those, as they power the anti-tamper devices. If you interrupt the power supply, all four circuits are made simultaneously, and the explosive charge will detonate. It won’t,’ he added, ‘trigger the bomb, but you won’t be around to appreciate it.’
He pointed at the mass of cables. ‘You have to cut the following seven wires, in this sequence,’ he said, and gave Richter a sheet of paper on which he had written the colour coding of the wires, and the order in which they were to be severed.
‘And that disarms the bomb?’ Richter asked.
‘Of course not,’ Dewar said, shaking his head. ‘That just means you can shift all this crap—’ he gestured at the wires ‘—and see the weapon. Now watch.’ He bent down and undid four butterfly nuts, then lifted out a large aluminium plate in the centre of which was a sealed box and around the box most of the wiring. ‘The box,’ he said, ‘contains about four kilos of plastic explosive, but once the wires are cut there’s no further danger from it.’ He put the plate down carefully on the floor beside the box, and they both looked inside again.
‘This weapon,’ he began, ‘wasn’t armed. That is to say, the firing circuits and all the other components are present, but the connections hadn’t been made. I presume that this would have been done once the weapon had been finally positioned.’ He pointed at a black plastic box with eight cables emerging from it. ‘This box is the link to the power supply. The weapon can be powered either by a mains supply – one hundred and ten or two hundred and forty volts alternating current, or by a twelve-volt direct current from a battery pack like the one in this container. In fact,’ he continued, ‘we believe it would normally be powered by the mains with the battery pack as a standby, as the circuitry incorporates a battery charger.
‘Now listen carefully. When you look at the weapon in Gibraltar, you will probably see a cable entering the box, just here.’ He pointed. ‘That will be the power supply. Again, as with the anti-handling devices, don’t interfere with it. This weapon doesn’t incorporate any kind of timing device, so we assume that it can only be detonated by an external signal of some sort.’
‘That is what we have been told,’ Richter assured him.
‘The trigger,’ Dewar said, ‘is here – this black cylinder with the four leads attached to it. On the Gibraltar weapon, there will also be one or more other wires which will be attached to whatever radio or communications device they are using to actuate it.’
Richter looked where he was pointing. The cylinder was about six inches in diameter and a foot long, and stuck at right angles out of the centre of the cylindrical bomb casing. ‘Do not attempt to disconnect or interfere with any of these leads. The only safe way to disarm the weapon is to physically remove the trigger.’
He looked at Richter. ‘Are you good with your hands?’
‘I hope so,’ Richter said.
‘So do I, because if you cock this bit up there’ll be a sodding great bang and most of Gibraltar will disappear. You,’ he added, ‘will be the first to know about it.’ Dewar wasn’t smiling. ‘The trigger is held in place by six Allen bolts – or rather Russian variants of them. These look like normal Allen bolts, with recessed hexagonal sockets in the heads, but differ in one important way. They have a left-hand thread, instead of the usual right-hand. That means that to undo the bolts you turn them clockwise.’
‘Why have they done that?’ Richter asked. ‘Just to be bloody awkward?’
Dewar glanced briefly towards the rear of the trailer. ‘If this was a French device, I’d agree with you,’ he said. ‘French engineering makes a point of complicating everything for no readily apparent reason. In this case, though, I think it’s just to ensure that the correct bolts are used. The pressures generated within a nuclear weapon at the moment of detonation boggle the mind, and it is essential that the trigger assembly remains in place for the period intended by the designer. These bolts have been specially made and have enormous tensile strength.’
He selected a ratchet handle from a socket set and attached a six-inch extension to it. Then he fitted an Allen bolt key to the end and snapped it into the head of one of the bolts. ‘You’ll find that they’ll take some shifting,’ he said. ‘We calculated the torque setting used at about three hundred foot-pounds. We removed all these earlier, so there’s no problem.’ Working quickly, he undid and removed five of the six bolts, then steadied the cylinder with one hand while he removed the last one. Then he put both hands around the cylinder and eased it slowly out of the bomb casing.
‘It’s quite heavy,’ he said, ‘but the important thing is to avoid it touching the sides of the casing as you remove it. If you do that, you could earth the cylinder and that might activate the trigger. I’m not saying it would, but it could, and I wouldn’t want to try it.’
‘Nor would I, thanks. And then?’
‘You’re almost there. With the trigger out of the sphere, put it on the floor and cut the four leads attached to it.’
Richter was puzzled. ‘Won’t that fire the trigger?’
‘Yes, of course. Oh – I see what you mean. This isn’t an explosive trigger; it’s mechanical.’ He held it up so that Richter could see it, and pointed at the sides. ‘These four bolts are recessed at present,’ he said. ‘When the trigger fires they will extend simultaneously and make contact with four electrically active panels on the inside of the hole in the bomb casing. That will complete the electrical circuit which triggers the explosive charge that actually fires the weapon. It’s an unusual system,’ he mused, ‘and there are some odd features in the design of the weapon itself.’
‘You might,’ Richter said, ‘get a chance to look at it more closely later on. Anything else I should know?’
‘Only to keep your fingers out of the way of the four bolts when you cut the wires attached to the trigger,’ he said, ‘but otherwise, that’s it.’
‘What about radiation from the weapon?’ Richter asked. ‘Once the trigger’s been removed, I mean.’
‘We’ve measured it, and it’s not significant,’ Dewar replied. ‘The fissionable material is obviously shielded within the bomb casing itself.’
‘OK, I’m happy with the disarming instructions, but please give me your mobile phone number now, and leave the mobile switched on for the next twenty-four hours. That’s just in case I meet any other problems down in Gibraltar.’
‘Of course,’ Dewar said. He wrote a number on a slip of paper and gave it to Richter.
‘Oh, one last thing,’ Richter said, ‘can I borrow the socket set and your pliers?’
