Take The Star Road (The Maxwell Saga) (25 page)

The Bosun smiled. "That's more like it! We won't do much better than break even getting there, but if they've got a full load waiting for us, that'll make the trip worthwhile."

Tomkins beckoned the waiter. "I think I can stomach something now. Scrambled eggs on toast, please, and more coffee."

"Right away, Sir."

"And put another table next to ours," the Bosun added as he spied three more members of
Cabot
's crew entering the restaurant. "Another shuttle must have just pulled in. You're about to become the busiest server in the place!"

###

They were able to begin loading cargo four days later, after the skipper pronounced himself satisfied with a full-power test run. The spacers donned their spacesuits and assembled in the main passage outside the midships holds. The Bosun busied himself dividing them into teams to begin loading containers for Rosalva.

Cardle looked up from his electronic clipboard. "Maxwell, you haven't assisted the Loadmaster yet, have you?"

"No, Bosun."

"It's high time you did. You're a Second Class now, so you need to start learning what goes into his job. I'll call him to tell him you're coming. Get out of your work gear and stow it, then report to him."

"Aye aye, Bosun."

The Third Mate, Eddie Boals, who was also the ship's Loadmaster, was sitting at his specialized console in an alcove off the bridge. Steve came up behind him and coughed gently.

"What is it, Spacer?" Boals asked without turning his head, intent on his displays.

"Sir, I'm Maxwell. The Bosun said - "

"Oh, yes! He called me about you. Here, take a seat." As Steve sat down beside him he continued, "At the moment I'm planning where to place cargo to optimize the ship's longitudinal stability."

"Yes, Sir. I recall learning during my training that longitudinal stability is very important when making a hyper-jump."

"That's putting it mildly!" Boals called up a three-dimensional diagram of
Cabot
. "Look here. Our midships point is calculated on three axes; front to back, top to bottom and side to side. Ideally we like to have our center of mass - of gravity, if you like - coincide with that point, so that the ship's perfectly balanced. With careful loading we can usually get it to within a few meters of where we want it on each of those axes. I've calculated the placement of those containers to optimize it. We'll finish the job by moving reaction mass between ballast tanks to fine-tune the adjustment.

"When the ship makes a hyper-jump, as you know, she's dragged into an artificial wormhole, a toroidal gravitic field generated ahead of her. It spits her out light-years ahead of where she started. Her longitudinal stability - in other words, the ship's tendency to continue in a straight line rather than pitch up or down, or yaw left or right, around her center of gravity - is absolutely critical for that maneuver.

"If our stability is out of whack by more than half a per cent, we might be pulled into the toroidal field off-course - in other words, at an angle. That would throw off our exit position. An error of only one degree would put us more than two hundred and sixty billion kilometers out of position at the end of a ten-light-year hyper-jump. If we're in deep space, navigating between planets, we can compensate for that in the next jump, but if our exit point was close to a star, or a black hole, or something like that, it might be a lot more tricky - you don't want to get too close, for obvious reasons! If the error is greater than two or three per cent, stresses on the ship's structure will become unsustainable. We'll be ripped apart, hull, cargo and crew." He shook his head vehemently. "I don't want to die any more than the next man, but I particularly don't want to die like that, thank you very much!"

"That makes two of us, Sir," Steve assured him very sincerely.

"There's a lot of material about the Loadmaster's job in the ship's library. I recommend you do a couple of hypno-study modules to learn the calculations involved - and give them more than passing attention. This is a critical function. If the Loadmaster gets things wrong, ships and people die!"

Steve spent the rest of the morning watching Boals at work and asking questions. The man operated like the conductor of an orchestra, checking the loaded mass of each container, directing spacers to put them in specific locations in the hold or move stacks of containers here and there until he was satisfied. As each section of hold was finished, the crew used restraints to strap everything in place and verify that it would be secure against the inertial forces generated by space flight. The size and quantity of straps, clamps, magnets and other securing devices illustrated all too clearly the potential magnitude of those forces.

"How do warships manage to balance their load, Sir?" he asked at one point. "I mean, aboard a freighter you've got holds spread the length and breadth of the ship. It's easy to move things around. Warships don't have so many or such big cargo spaces, so how do they fine-tune their longitudinal stability?"

"It has to be designed into them on the drawing board. It's a very complex problem. A warship's missiles are usually more than ten per cent of her loaded mass, and her consumable supplies are at least as much again. Once she's fired or used those things, she must still be longitudinally stable, even though her mass has been greatly reduced. What the designers do is position the missile cells in the middle third of the ship, so that when they're fired there isn't too much mass lost from fore or aft. They also fire partial missile salvos using a pattern across all of the cells, rather than taking all of them from one part of the main battery. That helps keep the ship's overall mass evenly distributed.

"As for consumables, a warship's storage is spread along the length of the ship. She tries to stow and use her stores in a balanced way. She has ballast tanks, like us, so she can distribute reaction mass to balance the ship. Taken in combination, those measures usually work."

"Er... you said 'usually', Sir. What if they don't work for some reason?"

The Third Mate shrugged. "Then the ship's in a world of hurt! She'll have to dump excess weight in order to restore stability, perhaps by firing off more of her missiles, or jettisoning an empty missile cell, or supplies, or reaction mass. Needless to say, no-one likes to do that, given the hazard to astrogation posed by space debris. Alternatively, another ship may be able to provide extra ballast. Absent either of those alternatives, the ship won't be able to hyper-jump safely. She'll be stuck where she is until another ship can bring her what she needs to solve the problem. If there are enemies around at the time, or if she doesn't have any way of sending for help, or doesn't have enough supplies to wait until help arrives... well, that's just her crew's horrible luck, I guess."

"I get it, Sir. Not a good position to be in."

"Not good at all!"

Another half-hour passed in silence as the Third Mate continued to calculate masses and balance points, and move the cargo accordingly. Steve watched closely, and occasionally used his PIA to look up a point in the ship's library.

During a brief pause, Boals turned to Steve. "You haven't yet spent any time on the bridge during passage, have you?"

"No, Sir. I did a three-month stint in Engineering, and another in hull maintenance."

"That makes sense. You were a Third Class until very recently, and those areas are less complex, better suited to entry-level spacers. However, you're a Second Class now, and you need to begin learning about the various consoles on the bridge that we use to operate the ship when she's under way. I'll have a word with the Bosun. I think you'll be best advised to start on the Navigation console for the next three months, then look at the Plot and Communications."

"Thank you, Sir. I'll look forward to it."

Chapter 17: May 17th, 2838 GSC

Cabot
's bridge was quiet. The only sounds were the whisper of air from the ventilating ducts, and the occasional murmur of voices as the duty watch consulted among themselves.

"How do they work out the system boundary for each type of star, Sir?" Steve asked the Second Mate and Navigating Officer, Lieutenant Feeny. He was seated next to him, learning to operate the support functions of the Navigation console. "I know it's the distance from the star within which our hyper-jump's toroidal gravitic field might be disrupted by the star's own gravity, but I'm not sure why its distance from the star differs from system to system."

"It's a complex process," Feeny explained. "The system boundary's usually portrayed as an oblate spheroid, centered on the star. The star's type and mass affect its radius, which is usually around a billion kilometers, plus-or-minus about ten per cent. The system boundary would be a pure sphere but for the mass, number and positions of planets and asteroids. They normally occur along the plane of the system - the level upon which most objects orbit the star - so they extend the system boundary along the plane. That's also why we arrive below the plane, and depart a system above it. It's to avoid those minor gravitic influences."

"Why not arrive above and depart below the plane, Sir? Who decides?"

"The present system was codified by United Planets convention a couple of centuries ago, in order to avoid unexpected encounters between arriving and departing ships. It applies throughout the settled galaxy. Individual planets can and do regulate it even more strictly. If they have heavy starship traffic - like Old Home Earth or Vesta, for example - they divide their system into zones for ships arriving from or departing in various directions, with others reserved for intrasystem traffic. They publish their navigation requirements as Notices to Spacers. Being a Lancastrian ship, we get ours through the Board of Admiralty, which updates its
Interstellar Pilot
every quarter. Every starfaring planet or polity sends its updates to the Transport Directorate of the United Planets. They receive everyone's updates, consolidate them into quarterly reports, and circulate them to all settled planets and interstellar polities, who redistribute them as they see fit."

"I get it. Does Rosalva have any special regulations?"

"Funny you should ask that. Up until a few months ago they didn't, but according to the latest Admiralty update, they do now."

"They do?" Captain Volschenk asked from his command console, frowning. "Why wasn't I informed about them, Pilot?"

"I assumed you'd received the latest update signal at Bedford, Sir. It was addressed to Commanding Officers and Navigating Officers, as usual."

"I don't recall seeing it. I'll check on that. What are Rosalva's requirements?"

"Sir, the
Interstellar Pilot
advises that Rosalva's been having trouble with piracy. As a result, the planet's implemented a convoy system for arriving and departing spaceships. We'll emerge plus-or-minus fifty million clicks from their designated arrival point, which will be marked by a spacebuoy beacon, orbited by one of their patrol craft. We'll join it at the beacon, then wait to be escorted to planetary orbit along with any other arrivals, Sir. They run inward and outward convoys, one every second day."

Volschenk frowned. "That could delay us. When did they institute this policy?"

"According to the
Interstellar Pilot
it came into effect four months ago, Sir. They don't have many patrol craft, so this allows them to concentrate traffic and escorts together, rather than have to sweep their entire system for intruders."

"Very well. Prepare a course to the beacon as soon as you locate it after we arrive. We'll cruise over to it at low power. No sense in having to kill too much momentum if we're going to rendezvous with other ships."

"Aye aye, Sir."

"On a different note, I'm glad to hear you asking plenty of questions, Maxwell," the Captain observed. "That's how you learn - and it keeps the rest of us on our toes, answering them." A subdued chuckle ran around the Bridge watch.

"Yes, Sir," Steve agreed. "I must admit, astrogation's fascinating. It's so complex!"

"That it most certainly is. Are we ready for our final hyper-jump, Pilot?"

"Aye aye, Sir. Course and energy level have been transmitted to your console, Sir."

"Thank you."

The Captain reached for his harness and strapped himself into his seat as the rest of the Bridge watch did likewise. He scanned his displays rapidly, then donned his headset and microphone. He pressed a button on the console.

"Command to Engineering. I'm showing only 87.1% on the capacitor ring charge. Why isn't it at 100%?"

There was a pause. Lieutenant Feeny hurriedly switched his console's audio to the Command channel so he and Steve could follow the conversation through their headphones.

The voice that replied wasn't the Chief Engineer, but one of his senior techs. "Engineering to Command. Sir, we had to divert some reactor power to our two cargo shuttles, to power up their own reactors and check out their systems. They've been dormant all through our refit, and weren't used to load our cargo for this trip - we used Bedford's shuttles to do that. We wanted to check them out thoroughly before they had to fly again. 87.1% is still plenty for our final hyper-jump, Sir."