and he sought to adapt the ingenious mechanisms so clearly diagrammed in his mind to the materials and needs of the moment. He looked up at the roof beams of the hut and a new idea dawned on him. But he put it aside – the crossbow came first.
Willis straightened, holding a flat spring. ‘This came from an auto – will it do for the bow?’
Armstrong tried to flex it and found it very stiff. ‘It’s very strong,’ he said. ‘Probably stronger than anything they had in the Middle Ages. This will be a very powerful weapon. Perhaps this is too strong – we must be able to bend it.’
‘Let’s go over that problem again,’ Willis said.
Armstrong drew on the back of an envelope. ‘For the light sporting bows they had a goat’s-foot lever, but that is not strong enough for the weapon we are considering. For the heavier military bows they had two methods of bending – the cranequin, a ratchet arranged like this, which was demounted for firing, and the other was a windlass built into the bow which worked a series of pulleys.’
Willis looked at the rough sketches and nodded. ‘The windlass is our best bet,’ he said. ‘That ratchet thing would be difficult to make. And if necessary we can weaken the spring by grinding it down.’ He looked around. ‘Where’s Peabody?’
‘I don’t know,’ said Armstrong. ‘Let’s get on with this.’
‘You’d better find him,’ Willis said. ‘We’ll put him on to making arrows – that should be an easy job.’
‘Bolts or quarrels,’ said Armstrong patiently.
‘Whatever they’re called, let’s get on with it,’ Willis said.
They found Peabody taking it easy in one of the huts, heating a can of beans. Reluctantly he went along to the workshop and they got to work. Armstrong marvelled at the dexterity of Willis’s fingers as he contrived effective parts from impossible materials and worse tools. They found the old grindstone to be their most efficient cutting tool, although it tended to waste material. Armstrong sweated in turning the crank and could not keep it up for long, so they took it in turns, he and Willis silently, Peabody with much cursing.
They ripped out electric wiring from a hut and tore down conduit tubing. They cut up reinforcing steel into lengths and slotted the ends to take flights. It was cold and their hands were numb and the blood oozed from the cuts made when their makeshift tools slipped.
They worked all night and dawn was brightening the sky as Armstrong took the completed weapon in his hands and looked at it dubiously. ‘It’s a bit different from how I imagined it, but I think it will do.’ He rubbed his eyes wearily. I’ll take it down now – they might need it.’
Willis slumped against the side of the hut. ‘I’ve got an idea for a better one,’ he said. ‘That thing will be a bastard to cock. But I must get some sleep first – and food.’ His voice trailed to a mumble and he blinked his eyes rapidly.
All that night the bridge had been illuminated by the headlamps of the enemy vehicles and it was obviously hopeless to make a sortie in an attempt to cut the cables. The enemy did not work on the bridge at night, not relishing being in a spotlight when a shot could come out of the darkness.
Forester was contemptuous of them. ‘The goddam fools,’ he said. ‘If we can’t hit them in daylight then it’s sure we can’t at night – but if they’d any sense they’d see that they could spot our shooting at night and they’d send a man on to the bridge to draw our fire – then they’d fill our man full of holes.’
But during the daylight hours the enemy had worked on the bridge, and had been less frightened of the shots fired at them. No one had been hit and it had become obvious that there was little danger other than that from a freakishly lucky shot. By morning there were but six bullets left for Rohde’s pistol and there were nine more planks in the bridge.
By nine o’clock Rohde had expended two more bullets and it was then that Armstrong stumbled down the road carrying a contraption. ‘Here it is,’ he said. ‘Here’s your crossbow.’ He rubbed his eyes which were red-rimmed and tired. ‘Professionally speaking, I’d call it an arbalest.’
‘My God, that was quick,’ said O’Hara.
‘We worked all night,’ Armstrong said tiredly. ‘We thought you’d need it in a hurry.’
‘How does it work?’ asked O’Hara, eyeing it curiously.
‘The metal loop on the business end is a stirrup,’ said Armstrong. ‘You put it on the ground and put your foot in it. Then you take this cord and clip the hook on to the bowstring and start winding on this handle. That draws back the bowstring until it engages on this sear. You drop a bolt in this trough and you’re ready to shoot. Press the trigger and the sear drops to release the bowstring.’
The crossbow was heavy in O’Hara’s hands. The bow itself was made from a car spring and the bowstring was a length of electric wire woven into a six-strand cord to give it strength. The cord which drew it back was also electric wire woven from three strands. The sear and trigger were carved from wood, and the trough where the bolt went was made from a piece of electric conduit piping.
It was a triumph of improvisation.
‘We had to weaken the spring,’ said Armstrong. ‘But it’s still got a lot of bounce. Here’s a bolt – we made a dozen.’
The bolt was merely a length of round steel, three-eighths of an inch in diameter and fifteen inches long. It was very rusty. One end was slotted to hold metal flights cut from a dried-milk can and the other end was sharpened to a point. O’Hara hefted it thoughtfully; it was quite heavy. ‘If this thing doesn’t kill immediately, anyone hit will surely die of blood-poisoning. Does it give the range you expected?’
‘A little more,’ said Armstrong. ‘These bolts are heavier than the medieval originals because they’re steel throughout instead of having a wooden shaft – but the bow is very powerful and that makes up for it. Why don’t you try it out?’
O’Hara put his foot in the stirrup and cranked the windlass handle. He found it more difficult than he had anticipated – the bow was very strong. As he slipped a bolt into the trough he said, ‘What should I shoot at?’
‘What about the earth bank over there?’
The bank was about sixty yards away. He raised the crossbow and Armstrong said quickly, ‘Try it lying down, the way we’ll use it in action. The trajectory is very flat so you won’t have much trouble with sighting. I thought we’d wait until we got down here before sighting in.’ He produced a couple of gadgets made of wire. ‘We’ll use a ring-and-pin sight.’
O’Hara lay down and fitted the rough wooden butt awkwardly into his shoulder. He peered along the trough and sighted as best he could upon a brown patch of earth on the bank. Then he squeezed the trigger and the crossbow bucked hard against his shoulder as the string was released.
There was a puff of dust from the extreme right of the target at which he had aimed. He got up and rubbed his shoulder. ‘My God!’ he said with astonishment. ‘She’s got a hell of a kick.’
Armstrong smiled faintly. ‘Let’s retrieve the bolt.’
They walked over to the bank but O’Hara
