1636 The China Venture – Snippet 32
On board the Rode Draak
Liu Xiang’s Eagle’s Claw was sailed into position by a skeleton crew. Once they got there, they quickly reduced sail. That was an easy task on a junk rig, as it could be accomplished by a single man on deck, easing up on the halyard until the desired number of panels had dropped down and been collected by the buntlines, like an upside-down Venetian blind.
The crew then threw over a crude sea anchor. It was in the conical shape of the fishing nets used for trawling, but with sail cloth in place of netting, a sort of underwater parachute. It would further slow the movement of the ship with the wind.
This accomplished, they lowered a small boat, clambered into it, and rowed to Zheng Zhilong’s flagship.
“You’re not going to tow the target?” asked von Siegroth, standing with Admiral Zheng Zhilong on the quarterdeck of the Rode Draak. “That would make for a better test.”
“Alas,” said the admiral, “we aren’t carrying a long enough tow line for any of my captains to feel comfortable towing a target in front of a crew whose gunnery skills are unknown to them. Or for me to be inclined to order them to do so. Perhaps another time. For now, a target moving slowly under reduced sail and a sea anchor suffices.”
Colonel von Siegroth studied the Eagle’s Claw. It had three masts, each bearing a single junk sail. The hull, however, had a more European appearance. This, then, was what the colonel had been told was called a lorcha; they had been developed by the Macaonese and were quite fast. It had eight gunports visible, but von Siegroth assumed that the guns had already been removed.
The principal source of information in Grantville concerning 19th century and older artillery were the books and magazines owned by the town’s ACW reenactors, and by Eddie Cantrell and his wargaming buddies.
Eddie had had quite a bit of information about the USS Constitution. During the War of 1812 she carried thirty long 24s on the gun-deck, sixteen 32-pounder carronades on the quarter deck, another six 32-pounder carronades on the forecastle, and one long 18 and two long 24s as bow-chasers. The Grantville literature gave the exact dimensions of the 32-pounder carronades carried by the Constitution‘s sister ship, the United States, and provided scale drawings of the classic carronade slide mount. Neither the carronade nor its mount had required any technology that the seventeenth century didn’t have already, just the commitment of resources that would otherwise have gone into casting more iron long guns and building more of the standard truck carriages.
Colonel von Siegroth cleared his throat. “So, Admiral Zheng, I understand that you have been aboard European warships. Their principal armament are the long guns; the very heaviest fire a 42-pound shot and have a barrel length of ten feet. Here in Asian waters, the heaviest long gun probably fires a 24-pound shot, and has a barrel length of nine to ten feet.
“This is a carronade. We have eight on the quarter deck, as you can see, and there are another eight below. It fires a heavier shot, 32 pounds, although the barrel is only a little over four feet. It weighs about two thousand pounds, whereas the long 24 weighs more than five thousand. It can be handled by a crew of four– fewer in a pinch–whereas the long 24 needs a dozen. And it can be fired more quickly, too.”
“So what’s the drawback?” asked Zhilong. “There has to be one.”
“It’s designed to use a smaller powder charge relative to the weight of the shot, and hence there is less force generated. The maximum range is less than that of a long gun firing the same shot.”
Von Siegroth did not volunteer any details as to the carronade’s interior design, but of course if Zhilong were to buy one, his foundrymen would be able to study it and discern that the powder chamber was narrower than the bore and that the windage, the clearance of the shot within the bore, was less than the norm for a long gun.
Zhilong glanced at the sea, as if gauging distances. “What sort of range are we talking about?”
“Well, it’s complicated. Point blank, you can reach a bit over three hundred yards, comparable to or better than a long 18 or 24. Which is overkill, since most battles are fought at one to two hundred yards. At five degrees elevation, it can reach something like twelve hundred yards. With a long 18, perhaps eighteen hundred yards. But you’d need a small miracle to hit a ship-sized target with either gun at those distances, I think. And a long 18 weighs twice as much and fires only half as frequently.”
“Man the starboard guns!” yelled Captain Lyell.
Lyell continued to give orders. The four starboard quarterdeck carronades were sponged out, cartridges loaded and rammed home, shot loaded, and the guns run out.
“We will begin by demonstrating the effect of a single gun, so there is less uncertainty as to what is happening,” explained von Siegroth. He raised his hat.
Seeing this, Captain Lyell commanded, “Gun number one, fire on Colonel von Siegroth’s command.” It was a deviation from protocol to yield control to a passenger, but von Siegroth was an artillery expert. Its present gun captain was an artilleryman brought on board by von Siegroth to train the gun crews with the carronades.
“As you can see, Admiral, the carronade has an unusual mount.” The carronade had a mounting block cast on the bottom of the gun. The gun crew had slid the mounting block back on its bed to bring the muzzle inboard for loading, and then slid it back out to the firing position. A long gun would be mounted on a four-wheeled sea carriage, and rolled back and forth. More men were needed to control its movement.
“When it is fired, the gun will recoil back along the slide, bringing it back to the loading position.”
The bed had a pivot underneath one end and complementary rollers under the other. The pivot engaged a socket that in turn was attached to the bulwark.
“Captain Lyell advises me that usually the guns are fired directly broadside, but in a chase we would point forward and if fleeing we’d point aft. To traverse a long 24 to point ahead or astern, two tackle men and two handspike men would be needed to ease up the barrel and turn the carriage. However, traversing is easy with a carronade mount, as it can just be rolled around the pivot point. One or two men could do the job with the aid of the side tackles.”
Zhilong grumbled, “Until I started building a new line of war-junks, our ship guns didn’t even have carriages; they could only fire directly broadside. I can see the advantage of the new mount from a gunhandling perspective, but it leads to less flexibility. You can’t as readily transfer a gun from one deck to another, let alone one ship to another.”
‘”The up-timers also had gunnades,” said von Siegroth, “which had barrels like a carronade but were mounted on a normal sea carriage. They could be pointed upward more sharply, and merchant ships used them to destroy enemy rigging. And small gunnades were also used as warship launch guns.”
Now the gun captain was having the crew adjust the elevation. Although the Rode Draak forecastle deck was considerably higher than the main deck of the junk, the range or the roll were great enough, apparently, to warrant a slight elevation.
“You’ll note that to elevate the guns, we use a screw instead of quoins.” Quoins were wooden wedges inserted under one end of the barrel. “It is more economical of manpower, and smoother.” The elevating screw had been drawn by Leonardo da Vinci, but in the old time line, it was not used in artillery until 1650, and then on land. “The screw engages a screw hole in the cascabel. But I must admit that quoins are faster if you need to make a big change quickly,” von Siegroth added.
“Gun One, fire when you bear!” he yelled to the gun captain. The Rode Draak was now even with the target junk, and it reduced sail to keep it that way.
“Clear the gun!” the gun captain called out in turn, and his men got out of the way. The recoil on the carronade was ferocious. It was Newton’s Laws at work; momentum had to be conserved, and while the muzzle velocity of a 32-pounder carronade was relatively low, the mass of the shot was so high that it had almost twice the momentum of that fired from a 9-pounder long gun. Yet the latter had sixty percent more mass, and thus inertia, to resist the recoil. While there was some friction from the slide mount, the breech rope was necessary to keep the fired gun from dismounting.