Independent and Tramp Traders

Kytheros wrote:

kzt wrote:Securing 20 million tons of steel girders against 5cm/sec^2 maneuvering of a docking thruster is not at all like securing 20 million tons of steel girders against the 500m/sec^2 of 50 gravities of a wedge.

50 gravities is soakable by standard grav plating, I'm pretty sure.
Even without that, as long as the inertial compensator is functional, any wedge-based acceleration is meaningless, and the effects of maneuvering thrusters can be handled by the grav plating. And if your compensator isn't functioning properly, you're going to keep to the accel your plating can handle while on your way to the nearest place to repair or replace your compensator.

That being said, you'd still need to do some degree of securing the cargo, as you want it to be organized on loading and remain organized while off-loading, and accidents can happen. Much of that would probably be handled through some degree of automation, though.

Sure, given a 3 meter deck. Given a 250 meter deep cargo bay, not so much. Plus a blown breaker means the ship gets torn in half as a billion tons of steel girders slams into the aft bulkhead.

Kytheros wrote:

kzt wrote:Securing 20 million tons of steel girders against 5cm/sec^2 maneuvering of a docking thruster is not at all like securing 20 million tons of steel girders against the 500m/sec^2 of 50 gravities of a wedge.

50 gravities is soakable by standard grav plating, I'm pretty sure.
Even without that, as long as the inertial compensator is functional, any wedge-based acceleration is meaningless, and the effects of maneuvering thrusters can be handled by the grav plating. And if your compensator isn't functioning properly, you're going to keep to the accel your plating can handle while on your way to the nearest place to repair or replace your compensator.

That being said, you'd still need to do some degree of securing the cargo, as you want it to be organized on loading and remain organized while off-loading, and accidents can happen. Much of that would probably be handled through some degree of automation, though.

It appears from some of the combat scenes that even a fully functional compensator doesn't 0 out all external accelerations; unexpected ones from missile impacts can still ring the hull like a bell. I assume thats one reason the bridge stations feature shock frames for chairs.

For probably slightly different reasons I suspect that grav plates don't automatically cancel out accelerations; their strength has to be computer adjusted to cancel out accelerations. That's easy to fairly quickly do if you're accelerating in a constant direction. But I suspect it's impractical to use them to make docking maneuvers internally imperceptible. A thruster than fires just a tad late; or runs a touch ragged would create a brief mismatch as the computer anticipated acceleration didn't quite match the actual. Far better to strap down, or otherwise secure, the cargo so that you don't need to worry about a little (or fairly big) bump starting an avalanche.

Weird Harold wrote:

SJLee wrote:A couple of you have made reference to the cost of even a small tramp-style ship, could you provide a rough estimate of the cost?

ten dollars-per-pound?

IIRC, there are some mentions that pirates could fence even a small freighter for a billion dollars (manticoran.) But dollar amounts are really meaningless without knowing the cost of gold or the price of a loaf of bread; the length of a mortgage is a better guide -- there are a couple of mentions of mortgages in textev, IIRC.

IIRC, Honor as CO of CL-56 Fearless was making ~$60,000 a year as her base salary at Basilak. An O-5 is in our society at the top third of the middle-middle class, but is not paid exhorbitantly above that of people with 10 years or more experience and some post-graduate education or a damn good skilled trade with experience.

If you have ever had to deal with a boat, a dock, a tidal current and wind (sometimes any two, sometimes all at the same time) you will understand the difference between the gentile touch of power to slow a bit more or slightly change direction and HOLY !!!! BRACE FOR COLLISION!!!

Having a load (any load or part of a load) shift is cause for concern. When the load moves it WILL have an effect on any number of things including the stability of the vessel and either catching something between the load and something solid (mind you fingers, toes and torso) or will perhaps break off the "something solid" and take that along with it. Shifting weight causing a ship to roll to where it starts taking on water or just keep rolling till it isn't going to come back is "to be avoided".

Even if you can't quote formulas for inertia, you learn fairly quickly that there is a very close relationship to the amount of stuff moving and: how much/how quickly (ususaly NOT really quickly) and how early you want to start applying forces to slow down or change direction of a vessel.

I suspect that the freighters in the honoverse are using a combination of physical clamping (like securing shipping containers) and rigging to hold things in position in the cargo areas. tractor/pressor beams sound really good but if you lose power (to the units involved or areas of the ship) you lose the control of the cargo involved. We haven't been show this specifially but we do have some idea of things like pods and small craft (up through pinnacles and combat shuttles) being clamped into place in their bays. Pods have to be secured such that they can be fed onto lanching rails. That could either have been done in formal magazines (with rails and handling equipment or ammunition shipping containers set to feed rails.

In the end, some kind of physical restraint is probably involved.

Brigade XO wrote:
snip

In the end, some kind of physical restraint is probably involved.

Necessary unless some form of reliable non-physical restraint is used. Even then, remember the circuit breaker problem mentioned earlier. Wasn't there a scene, IIRC in OBS where they needed to move missiles manually from a non-functional ammo queue to a functional one, and someone got mostly crushed when a hit jolted the ship

yep as you say it was on bassilisk station, moving missiles from magazine to another. Bosun Mcbride was badly hurt and harkness just missed being hurt as well

Dauntless wrote:yep as you say it was on bassilisk station, moving missiles from magazine to another. Bosun Mcbride was badly hurt and harkness just missed being hurt as well

Though as a counter-point, for freighters not designing for battle damage and the power loss it might include, is that tractors or pressors are considered safe and reliable enough that there is a dining area in Dempsey's (IIRC) "floating" in mid-air by use of one or both of those system. (The one where Honor and her party got attacked by gunmen; and defended by her new Armsmen).

If it can be considered safe enough for continuous use in civilian restaurants it must be damned reliable indeed; since that doesn't appear to be a fail-safe situation.

I would expect such a high end restaurant to have back-up generators, ready to kick in the moment the power flickers.

wouldn't do to have the restaurant sued by heirs due to something beyond the ability to control due to external power.

there probably do use a presser/tractor arrangement but for insurance have to have a basic physical method as well.

kzt wrote:Securing 20 million tons of steel girders against 5cm/sec^2 maneuvering of a docking thruster is not at all like securing 20 million tons of steel girders against the 500m/sec^2 of 50 gravities of a wedge.

Jonathan_S wrote:

Kytheros wrote:50 gravities is soakable by standard grav plating, I'm pretty sure.
Even without that, as long as the inertial compensator is functional, any wedge-based acceleration is meaningless, and the effects of maneuvering thrusters can be handled by the grav plating. And if your compensator isn't functioning properly, you're going to keep to the accel your plating can handle while on your way to the nearest place to repair or replace your compensator.

That being said, you'd still need to do some degree of securing the cargo, as you want it to be organized on loading and remain organized while off-loading, and accidents can happen. Much of that would probably be handled through some degree of automation, though.

It appears from some of the combat scenes that even a fully functional compensator doesn't 0 out all external accelerations; unexpected ones from missile impacts can still ring the hull like a bell. I assume thats one reason the bridge stations feature shock frames for chairs.

For probably slightly different reasons I suspect that grav plates don't automatically cancel out accelerations; their strength has to be computer adjusted to cancel out accelerations. That's easy to fairly quickly do if you're accelerating in a constant direction. But I suspect it's impractical to use them to make docking maneuvers internally imperceptible. A thruster than fires just a tad late; or runs a touch ragged would create a brief mismatch as the computer anticipated acceleration didn't quite match the actual. Far better to strap down, or otherwise secure, the cargo so that you don't need to worry about a little (or fairly big) bump starting an avalanche.

I don't think the compensator affects any external forces of acceleration at all, just the wedge acceleration.
While I think grav plating would have issues with damping unexpected external accelerations, I suspect that the "thrusters" would be employing grav-driver tech and accelerating the reaction mass out, rather than relying on a fuel reaction, and as such the kinds of issues with non-standard accelerations would be functionally mitigated. Also, not knowing how the grav plates actually dampen acceleration forces felt ... it may be that within their limitations, they can soak however much they're set to soak or any amount less, and not need continuous adjustment - which would certainly make everything a lot simpler. We don't actually know how much force was imparted and negated in the instances you refer to, but missiles are respectably sized objects moving pretty fast, so I'd expect that they're hitting pretty hard, but how much of what was transferred actually was felt and how much (if any) was negated by grav plating is unknown.

That said, I fully agree that there would be some means of securing the cargo ... just that that means wouldn't need to be capable of taking the full undampened acceleration forces. Besides, I expect maneuvering thrusters on transports are probably run at very low accelerations, even for reaction thrusters - and very likely supplemented with or fully replaced by tractor beams for final approach.
Remember, even milspec structural stuff (admittedly a Masadan LAC) can fail under high accelerations, and I'd expect the requirements for that to be a lot more stringent. In Honor of the Queen, a pressure tank on one of the LACs that was being towed to Yeltsin from Masada broke free from its mounting and tore a hole through the ship. Sure, it was a Masadan LAC, but still, I'd expect the requirements for civilian cargo handling and securement to be much less stringent.

DDHvi wrote:

Brigade XO wrote:
snip

In the end, some kind of physical restraint is probably involved.

Necessary unless some form of reliable non-physical restraint is used. Even then, remember the circuit breaker problem mentioned earlier. Wasn't there a scene, IIRC in OBS where they needed to move missiles manually from a non-functional ammo queue to a functional one, and someone got mostly crushed when a hit jolted the ship

Dauntless wrote:yep as you say it was on bassilisk station, moving missiles from magazine to another. Bosun Mcbride was badly hurt and harkness just missed being hurt as well

True, however, I believe it was also mentioned that the automated transfer tubes between the port and starboard magazines were inoperable, thus, they had to do it manually.
Also mentioned in that scene was something called a "grav-collar", which would probably also be something applicable to manipulating cargo. That didn't negate inertia though.

What you can do (adding backups, surge protectors on all the gear including the backups) and what you are going to do isn't the same thing. Floating resturante, sure, lots of safety stuff and nobody expects the space station to get 1) attacked by invisiable weapons-which did happen 2) get rammed by accident or deliberately, 3) suffer massive power failure to primary, secondary and -in the case of the restaurant- a possible compleatly independent powered backup system.

I spent summers growing up living near a commercial loading facility that was taking crushed stone and putting it into barges for shipment. The tugs that delvered and removed the barges were really only around when making said deliveries. To shift both empty and full barges and to move the barges under the loading shute, there was a winch system using cables- 1" plus braided steel cables running though pully systems- that were attached to the bollards or cleats on the barges and pulled them. We had to go over there sometimes- long story- but every year the first time we would go we would get the same safety lecture from the guys doing the work. There was no "safety presentation" or sit down meeting. The first time you went to the little float dock at the back of the facility (which was the only place you dam well ever approched it from, John or his brother would come over and have the "conversation" The cable system worked just fine. All sorts of parts of it were invisble and under the piers. But some of it had to be out in the open as you had to both be able to attach ends to barges and the lengths and angles changed depending on when and where things we.
NO walking about when barges were being moved. Period. There was just no way to shield the docks and the deck (at least outside the load containment steel bulkhead side or end ways) on the top of the barges against a snapped cable. Steel stone barges -even empty- weigh a lot. Adding quite a few tons of crushed stone (and so pushing them deep into the water so they arn't floating like soap bubbles) and they take a lot of pressure to move...and to stop. Cables can (and did sometimes) snap. Long, braided steel cables moving faster than a snake. Things like a human body won't stop them. They just go and will cut though anything they hit, if they don't cut though it, they will make a good size tear on or dent in.
So while it was theoreticaly possible to make the system safer, they didn't and you just had to stay out of the danger zone (which was impressivly large) whenever they were working.