Shipyard Construction Rate

[MasterGwydion]

As I understand it, an 800-ton shipyard can produce about 1MCr of ship per day building a 400-ton ship. Is this correct?

If so, what if they are building a 200-ton ship as the only ship being built in the shipyard? Is that built at a rate of 2MCr of ship per day?

Also, on this same line of thought. This one is kind of for Geir. How are space stations built? For almost all things, the term space station just means a ship with no jump drive and only a minimal 0.5 M-drive, and they cannot maneuver in combat. How do you build a space station, as the rules state, without a shipyard twice the size of the space station? If it is built in a Shipyard in pieces and then assembled on site, then can larger ships be built outside of shipyards as well?

 

[Geir]

So, what we have here is a chicken and egg problem (the answer being "A dinosaur laid the egg", but that's neither here nor there). Built in sections, I would presume (but where did that shipyard that made the sections come from, you ask... it's turtles shipyards all the way down...)

I want to take another look at the construction rules buried in the Drinaxian Companion and maybe a clever sentence or two can resolve the conundrum. But basically, for something as static as a station, without needing to deal with center-of-mass thrust issues, atmospheric effects and planned separation of components (unplanned is a matter for combat rules or other critical hit resolution), it's just a matter of building a section at a time with the capacity of whatever building method is available and sticking them together.

 

[MasterGwydion]

So, what we have here is a chicken and egg problem (the answer being "A dinosaur laid the egg", but that's neither here nor there). Built in sections, I would presume (but where did that shipyard that made the sections come from, you ask... it's turtles shipyards all the way down...)

Just saying, ships now are built in pieces and assembled on site at the shipyard.

I want to take another look at the construction rules buried in the Drinaxian Companion and maybe a clever sentence or two can resolve the conundrum. But basically, for something as static as a station,

Everything is static until you add thrust. lol

without needing to deal with center-of-mass thrust issues, atmospheric effects and planned separation of components (unplanned is a matter for combat rules or other critical hit resolution), it's just a matter of building a section at a time with the capacity of whatever building method is available and sticking them together.

Okay... So I totally screwed up My initial post. I will go back and fix it. The CRB lists 1MCr/day, not per month. My bad.

What building rules in the Drinaxian Companion? You mean the ones with PWH? I hate those! lol. They do not mesh well with mining and construction drone rules from the Robot Handbook.

 

[Condottiere]

You need a fifty kilotonne hull, to have the full benefit of modular construction.

Or, maybe, just to be permitted modular construction, upto ninety percent.

 

[MasterGwydion]

You need a fifty kilotonne hull, to have the full benefit of modular construction.

Or, maybe, just to be permitted modular construction, upto ninety percent.

I also want to know how they built the 1.5 Million ton monitor in the Core Depot system. a 3million Dton Shipyard designed to just build one 1.5 Million Dton ship?

 

[Condottiere]

Depends.

If it's a planetoid:

 

[phavoc]

As I understand it, an 800-ton shipyard can produce about 1MCr of ship per day building a 400-ton ship. Is this correct?

If so, what if they are building a 200-ton ship as the only ship being built in the shipyard? Is that built at a rate of 2MCr of ship per day?

Also, on this same line of thought. This one is kind of for Geir. How are space stations built? For almost all things, the term space station just means a ship with no jump drive and only a minimal 0.5 M-drive, and they cannot maneuver in combat. How do you build a space station, as the rules state, without a shipyard twice the size of the space station? If it is built in a Shipyard in pieces and then assembled on site, then can larger ships be built outside of shipyards as well?

There is no good answer to your question. The MCr per day is a rule of thumb, but if you look at it too closely it falls apart. A teeny designer yacht with fabulously expensive fittings may cost more than a freighter 10x it size. So your build rate is trash. Similar analogies run up and down the spectrum.

Also, how does one model a shipyard that is fully staffed vs one that is missing 20% of its labor force? Or has a cheap boss who refuses to properly pay it's workers? Or has the 52nd century OSHA riding herd on the build queue? For a game you can't and you shouldn't.

Also, how would one differentiate shipyards that have reputations for higher quality/lower quality? More efficient/less efficient? In the real worlds some yards are like that, but the game just lumps all that into the same pot.

Shipyards may be super busy or not. For the same question you are asking, what if the yard is at overcapacity, should you decrease the build rate by 40% due to a building boom going on?

I'm a sucker for details and explanations, but there's a limit to what I expect a publisher to do vs. what I should do myself if I need that sort of detail or I think it's germane to the gaming sessions. I think few players will care because they don't play their campaigns with that sort of detail. If you tell them their custom ship is, by the book rules, expected to build in 9 months then you have a number. If they have lots of credits they can shave the period by 2 months for 3X the cost to reflect what the shipyard will charge (I'd almost never give a discount unless you feel a desperate need for that - it's just not how a business would want to function).

As far as how you build things... well, with 52nd century tech like antigrav, getting anything to orbit opens up a realm of things we cannot do today. The magical M-drives make things like station keeping a minor thought. Plus it's safe to assume zero g assembly is a pretty basic thing by then, so the obstacles we may have today would not be around. So long as you can either build the components planetside or else ship them in, it should not be a technological challenge - regardless of the size of the vessel or station being built. Modularity means you could build components on a production line and lift them into orbit or even on the ground for assembly. Look at how they build USN carriers today and then remove the lifting constraints you'd have. And that gives you your answer.

 

[Arkathan]

Look at how they build USN carriers today and then remove the lifting constraints you'd have. And that gives you your answer.

Maybe not the best example, since the carriers are built in an emptied lock that is big enough to lower beams in via those cranes that straddle it, until enough of the underside is built that it can float. I've seen it where they flooded before and after the flight deck was installed, or mostly installed.

More to the original point, a bay can handle 1MCr per day according to HG. However you want to break that down is how it goes down. It makes sense from a crane/heavy equipment standpoint, but not from one of manpower. The updated HG says you need one crewman for each 10 tons of yard (5 tons of ship capacity). So when working on a smaller ship, you should be able to split the crew and have the same number working on two ships or twice the number working on the same 1/2 sized ship.

So, is the fabricator and crane the limiting factor? Could you double up the crew and get twice the ship built based on person-hours?
Or would the various crews working on different systems constantly be getting in each other's way? I suspect that an underutilized bay, with full personnel employed on a project would be able to complete a ship ahead of schedule, but not twice as fast.

 

[MasterGwydion]

There is no good answer to your question. The MCr per day is a rule of thumb, but if you look at it too closely it falls apart. A teeny designer yacht with fabulously expensive fittings may cost more than a freighter 10x it size. So your build rate is trash. Similar analogies run up and down the spectrum.

Also, how does one model a shipyard that is fully staffed vs one that is missing 20% of its labor force? Or has a cheap boss who refuses to properly pay it's workers? Or has the 52nd century OSHA riding herd on the build queue? For a game you can't and you shouldn't.

Also, how would one differentiate shipyards that have reputations for higher quality/lower quality? More efficient/less efficient? In the real worlds some yards are like that, but the game just lumps all that into the same pot.

Shipyards may be super busy or not. For the same question you are asking, what if the yard is at overcapacity, should you decrease the build rate by 40% due to a building boom going on?

I'm a sucker for details and explanations, but there's a limit to what I expect a publisher to do vs. what I should do myself if I need that sort of detail or I think it's germane to the gaming sessions. I think few players will care because they don't play their campaigns with that sort of detail. If you tell them their custom ship is, by the book rules, expected to build in 9 months then you have a number. If they have lots of credits they can shave the period by 2 months for 3X the cost to reflect what the shipyard will charge (I'd almost never give a discount unless you feel a desperate need for that - it's just not how a business would want to function).

As far as how you build things... well, with 52nd century tech like antigrav, getting anything to orbit opens up a realm of things we cannot do today. The magical M-drives make things like station keeping a minor thought. Plus it's safe to assume zero g assembly is a pretty basic thing by then, so the obstacles we may have today would not be around. So long as you can either build the components planetside or else ship them in, it should not be a technological challenge - regardless of the size of the vessel or station being built. Modularity means you could build components on a production line and lift them into orbit or even on the ground for assembly. Look at how they build USN carriers today and then remove the lifting constraints you'd have. And that gives you your answer.

Yeah, the rule specifically states that this 1MCr per day thing is an average, just like Officer's Pay is listed as 5,000Cr/mo, but this is an average. Better officers are paid more. Lesser officers are paid less. It is an average. Says so in the book. So, the book already gives you wiggle room. I am just trying to figure out, what that wiggle room would look like mechanically. Does it mean that if you use twice the tonnage of shipyard required to build a ship, you build it at 2MCr per day or is it just an efficiency thing? I am sure that there are other ways and other reasoning that could be used for this as well, but off the top of My head the example that came to mind was doubling of how much shipyard was used.

I actually asked before, in a different thread, what happened if you used a component such as a shipyard or a Manufacturing Plant and had less than the ideal number of workers. The consensus was that you reduced output by the same percentage you are short workers. This seemed to work well. I would also guess that average skill level of the workers would play into this as well, but that is getting too much like FFS for Me. I own the book, but almost never use it. I loved designing ships and weapons and power systems from that book when I was younger. Now that I am not younger, my brain just looks at FFS and says, "Ufff! I don't want to math! " lolz

 

[Condottiere]

You could get very specific about shipbuilding capacity.

If the result is balanced, or accurate, who knows?

 

[MasterGwydion]

You could get very specific about shipbuilding capacity.

If the result is balanced, or accurate, who knows?

True. No idea is this is balanced or not. I just figured there must be some differences in the building speeds of shipyards, since the book says there is variation, but I have found no rules that illustrate that effect.

 

[Condottiere]

You could ask yourself, what do you need to build a spacecraft?

If you need to build the ship components yourself, or you could buy them off the shelf.

System integration, if you have everything.

It's possible, some spacecraft (designs) are do it yourself assembly kits.

 

[MasterGwydion]

You could ask yourself, what do you need to build a spacecraft?

If you need to build the ship components yourself, or you could buy them off the shelf.

System integration, if you have everything.

It's possible, some spacecraft (designs) are do it yourself assembly kits.

The way I do it is house rules. Shipyard is good for 1MCr worth of stuff per day for whatever size craft I am building. I use the 50% cost rule for building things because it makes My life easy with math. In reality everything would have a different percentage, but that is too much of a headache, so I kept it simple. If you have 100 tons of Advanced Machine Parts (7.5MCr) I take half of that price off of the cost of the ship for how long it takes to make. Obviously, the system breaks down if you supply too many materials, so I usually use an artificial limit of 50% the value of the ship. So, if you want to build your ship faster than double speed, you will need to use more shipyard space to assemble the parts faster.

 

[Condottiere]

Could be modified by the skill of the labour force.

 

[MasterGwydion]

Could be modified by the skill of the labour force.

Should be, but that is a whole other level of complexity that I just didn't feel like figuring out. lol

 

[phavoc]

Maybe not the best example, since the carriers are built in an emptied lock that is big enough to lower beams in via those cranes that straddle it, until enough of the underside is built that it can float. I've seen it where they flooded before and after the flight deck was installed, or mostly installed.

More to the original point, a bay can handle 1MCr per day according to HG. However you want to break that down is how it goes down. It makes sense from a crane/heavy equipment standpoint, but not from one of manpower. The updated HG says you need one crewman for each 10 tons of yard (5 tons of ship capacity). So when working on a smaller ship, you should be able to split the crew and have the same number working on two ships or twice the number working on the same 1/2 sized ship.

So, is the fabricator and crane the limiting factor? Could you double up the crew and get twice the ship built based on person-hours?
Or would the various crews working on different systems constantly be getting in each other's way? I suspect that an underutilized bay, with full personnel employed on a project would be able to complete a ship ahead of schedule, but not twice as fast.

I was referring to how they installed the bridge section - which appears was built and lifted whole on to the hull. I think they did the same with Zumwalt superstructure.

I've seen old images of German Uboats (Type 23 I think) that they built in sections and welded together. And there was a cruise ship they added a pretty big section to by cutting it in half. The section was built in Italy (I think) and towed to Germany (or maybe it was Netherlands...it's been a while) where it was put together.

So it seems reasonable that similar things could take place for Traveller shipyards. Final fittings / wiring and such are done once the hull is built, but it does lend itself to a faster construction time than normal. Just how much faster and what, if any cost savings, there are would be guesswork. As fas as I can tell the process can save time but may not save much actual cost- though the concept of time is money should still hold true. It's just a complicated question to come up with a good reasonable answer to.

 

[Condottiere]

In late 1916, two British destroyers of the 6th Flotilla in the Dover Patrol—Nubian and Zulu—were badly damaged by German attacks in the English Channel. Nubian's bow had been destroyed by a torpedo from a German torpedo boat on 27 October in the Battle of Dover Strait, while Zulu had her stern blown off by a mine in the Channel on 8 November, and was towed to Calais.[3] Both wrecks were then towed to Chatham Dockyard, where a complete destroyer was constructed by joining the foreparts of Zulu with the stern of Nubian,[4] and despite a 3.5 inches (89 mm) difference in beam,[2] the unique operation was successful.[5] The ship was renamed Zubian by Admiral Reginald Bacon, the commander of the Dover Patrol.[6] The hybrid destroyer was commissioned on 7 June 1917.[7] The choice of name caused confusion among the German Imperial Admiralty Staff, who knew of no such ship under construction.[8]

 

[GabrielGABFonseca]

This is not directly an answer to the question posed in the original post, but I thought you might find it interesting nonetheless;

The linearity of ship construction if strictly following the HG2022 rules bothered me a lil' bit — sure, larger ships take more time to build, but one needs to take into account that a lot of the effort of building a ship is its hull, and when it comes to hulls, the square-cube law comes into play; if you quadruple the volume of an object whilst maintaining its shape, its surface area will only have increase by a factor of 2. So, in theory, if you were to make a copy of a 100 dTon ship, but four times bigger at 400 dTons, its surface area would only be twice as large and the construction time would be somewhere between 2 and 4 times as long.

Following that line of reasoning, I concocted the following house rule: the actual construction time of a ship is given by assuming the base 1MCr/Day construction rate, which is then multiplied by a size factor that is calculated as: 10 * (√x)/x, where 'x' is the ship's tonnage. For ships of 100 dTons, this modifier is exactly 1.

So as an example, using the rules as-written in the High Guard 2022 book, a Beowulf-class Type-A Free Trader, which costs MCr46.242 and is a TL12 ships (Construction Time Reduction of 90%) would take 46.242 * 0.9 = 41.6178 days to build.
Using the above house rule, it'd take that same time but multiplied by a factor of 10 * √200/200 = ~0.7071 so the construction time would be 41.6178 * 0.7071 = ~29.4279 days, or just shy of a month*.
*Be that the Imperial Calendar 28-day 'month' or the real-world 30-day month.

Applying the same maths to a much larger ship, such as a Tigress:
A MCr356830.9335, TL15 ship would, rules-as-written, take 356830.9335 * 0.6 = 214098.5601 days; in other words, about half a millennium and a few decades. Even with the additional 90% reduction for modular construction of ships of 50,000 or more dTons would only bring that down to 58.6 years.
Using the house rule, we find that the Tigress would have a size multiplier of 10 * √500000/500000 = ~0.01414213562, so its construction time would be 214098.5601 * 0.01414213562 = 3027.81087298 days, or some 8.3 years. If using the modular construction reduction as well, it'd bring it down to 302 days.

Amusingly, this houserule brings construction times much more in-line, although not exactly so, to the ship construction times as given in Classic Traveller modules (a Tigress took some 56 months to build according to Supplement 9: Fighting Ships if singly, and 40 in quantity).

Edit: As a further exploration of this houserule; for ships under 100 dTons, the multiplier is actually larger than one, so it implies it takes more time to construct a small craft than the straight '1 Day per MCr' rule would imply. This has some interesting consequences:

A Shuttle (95 tons, MCr14.6745, TL12) would take 14.6745 * 0.9 * (10 * √95/95) = ~13.55 days to build under the houserule.
A Light Fighter (10 tons, MCr9.432, TL12) would take 9.432 * 0.9 * (10 * sqrt(10)/10) = ~26.844 days to build.

At first it might be confusing for a craft that's one-fifth the size of the other to take nearly twice as long to build, but I actually find this quite reasonable; one's a military-spec craft built to more exacting tolerances, whereas the other is a glorified flying tin can.

 

[Terry Mixon]

This is not directly an answer to the question posed in the original post, but I thought you might find it interesting nonetheless;

The linearity of ship construction if strictly following the HG2022 rules bothered me a lil' bit — sure, larger ships take more time to build, but one needs to take into account that a lot of the effort of building a ship is its hull, and when it comes to hulls, the square-cube law comes into play; if you quadruple the volume of an object whilst maintaining its shape, its surface area will only have increase by a factor of 2. So, in theory, if you were to make a copy of a 100 dTon ship, but four times bigger at 400 dTons, its surface area would only be twice as large and the construction time would be somewhere between 2 and 4 times as long.

Following that line of reasoning, I concocted the following house rule: the actual construction time of a ship is given by assuming the base 1MCr/Day construction rate, which is the multiplied by a size factor that is calculated as: 10 * (√x)/x, where 'x' is the ship's tonnage. For ships of 100 dTons, this modifier is exactly 1.

So as an example, using the rules as-written in the High Guard 2022 book, a Beowulf-class Type-A Free Trader, which costs MCr46.242 and is a TL12 ships (Construction Time Reduction of 90%) would take 46.242 * 0.9 = 41.6178 days to build.
Using the above house rule, it'd take that same time but multiplied by a factor of 10 * √200/200 = ~0.7071 so the construction time would be 41.6178 * 0.7071 = ~29.4279 days, or just shy of a month*.
*Be that the Imperial Calendar 28-day 'month' or the real-world 30-day month.

Applying the same maths to a much larger ship, such as a Tigress:
A MCr356830.9335, TL15 ship would, rules-as-written, take 356830.9335 * 0.6 = 214098.5601 days; in other words, about half a millennium and a few decades. Even with the additional 90% reduction for modular construction of ships of 50,000 or more dTons would only bring that down to 58.6 years.
Using the house rule, we find that the Tigress would have a size multiplier of 10 * √500000/500000 = ~0.01414213562, so its construction time would be 214098.5601 * 0.01414213562 = 3027.81087298 days, or some 8.3 years. If using the modular construction reduction as well, it'd bring it down to 302 days.

Amusingly, this houserule brings construction times much more in-line, although not exactly so, to the ship construction times as given in Classic Traveller modules (a Tigress took some 56 months to build according to Supplement 9: Fighting Ships if singly, and 40 in quantity).

Maths... My eyes just rolled back in my head.

 

[Arkathan]

I was referring to how they installed the bridge section - which appears was built and lifted whole on to the hull. I think they did the same with Zumwalt superstructure.

I've seen old images of German Uboats (Type 23 I think) that they built in sections and welded together. And there was a cruise ship they added a pretty big section to by cutting it in half. The section was built in Italy (I think) and towed to Germany (or maybe it was Netherlands...it's been a while) where it was put together.

So it seems reasonable that similar things could take place for Traveller shipyards. Final fittings / wiring and such are done once the hull is built, but it does lend itself to a faster construction time than normal. Just how much faster and what, if any cost savings, there are would be guesswork. As fas as I can tell the process can save time but may not save much actual cost- though the concept of time is money should still hold true. It's just a complicated question to come up with a good reasonable answer to.

Bridge: Yes.

Multiple Yard/bays: Yes, and I'd call it the norm for larger ships.
Multiple bays working on a ship IS the best way to beat the 1MCr per day limit... but you'd either need to own the yards or pay them for the expedited service.