General Construction time - why so long?

[Condottiere]

In regard to big ticket items, like capital calibre cannons, research and development, system integration with ship and turntable platform, ammunition compatibility, mechanical and electrical teething problems, and gunnery training.

Sometimes, when you're in a hurry, you just use those that happen to be in storage.

 

[whartung]

If there's a large enough demand for a particular family of spacecraft, it's probably worthwhile for a shipyard to make it modular and use assembly line production, and the modules could be built to a common standard, that allows performance variations on a plug and play platform.

Well as anything over time, production rises to meet demand.

We just don't know what the demand is.

How many Free Traders or Scout ships need to be produced each year? With a 40 year working life, in theory, 2.5% of the fleet would need to be produced simply to keep up with losses, much less actual growth.

I mean, at a casual glance, the number of cars that we make each year is, honestly, staggering. 17 million sold in the US market last year. 46000 cars manufactured each day.

My car, Jeep Grand Cherokee, they make over 660 per day out of a single plant. Almost 1 every 2 minutes. I mean, wow. (and clearly they don't work every day, or 24hrs per day, so I'm sure the numbers are even zanier.)

 

[Condottiere]

A car platform is a shared set of common design, engineering, and production efforts, as well as major components over a number of outwardly distinct models and even types of cars, often from different, but somewhat related marques.[2] It is practiced in the automotive industry to reduce the costs associated with the development of products by basing those products on a smaller number of platforms. This further allows companies to create distinct models from a design perspective on similar underpinnings.[2]

A basic definition of a platform in cars, from a technical point of view, includes: underbody and suspensions (with axles) — where the underbody is made of front floor, Rearfloor, engine compartment and frame (reinforcement of underbody).[3] Key mechanical components that define an automobile platform include:
The floorpan, which serves as a foundation for the chassis and other structural and mechanical components
Front and rear axles and the distance between them - wheelbase
Steering mechanism and type of power steering
Type of front and rear suspensions
Placement and choice of engine and other powertrain components
Platform sharing is a product development method where different products and the brand attached share the same components.[4] The purpose with platform sharing is to reduce the cost and have a more efficient product development process.[5] The companies gain on reduced procurement cost by taking advantage of the commonality of the components. However, this also limits their ability to differentiate the products and imposes a risk of losing the tangible uniqueness of the product. The companies have to make a trade-off between reducing their development costs and the degree of differentiation of the products.[4]
Characteristics of a joint platform[edit]
Platform sharing is often used by different brands within a group of companies. Essential characteristics of a commonly used platform are the Chassis and the Drive Unit. There is a fluent transition, to what extent two or more different Motorcycle models draw on the same components:
Structural equality: Only the brandlogo, front fairing, fuel tank and, if applicable, headlights and rear lights, are different. Structurally equal vehicles are often manufactured at the same production line.
Same platform: Different fairings have the same fixation points, so that the fork, wing, engine, transmission, etc. can be switched out easily.
The remaining parts of the vehicle are divided into "head"- and system parts. A "head"-part could be the bodywork, or fuel tank, which can significantly differ from one another (cf. BMW GS-Model).
System parts are actually common parts (COP = Carry Over Parts), which are copied and adjusted to the particular model. E.g.: Wheels or wagons, totally identical, just another model symbol.
Platform sharing among brands[edit]
One of the first car companies to use this product development approach was General Motors for in 1908. General Motors used a single chassis for certain class of model across most of its brands like Chevrolet, Buick, Pontiac and Oldsmobile. Later Chrysler Corporation would use the same for Plymouth and DeSoto and Dodge cars. Ford followed the same principle for Ford and Mercury in US markets. The chassis unit was common with many shared mechanical components while the Exterior styling and Interior trims were designed according to its individual brand and category.


...

Differences between shared models typically involve styling, including headlights, tail lights, and front and rear fascias. Examples also involve differing engines and drivetrains. In some cases such as the Lexus ES that is a Toyota Camry, "same car, same blueprints, same skeleton off the same assembly line in the same factory", but the Lexus is marketed with premium coffee in the dealership's showroom and reduced greens fees at Pebble Beach Golf Links as part of the higher-priced badge.[17]
Platform sharing may be less noticeable now; however, it is still very apparent. Vehicle architectures primarily consist of "under the skin" components, and shared platforms can show up in unusual places, like the Nissan FM platform-mates Nissan 350Z sports car and Infiniti FX SUV. Volkswagen A platform-mates like the Audi TT and Volkswagen Golf also share much of their mechanical components but seem visually entirely different. Volkswagen Group and Toyota have both had much success building many well differentiated vehicles from many marques, from the same platforms. One of the least conspicuous recent examples is the Chevy Trailblazer and Chevy SSR; both use the GMT-360 platform.

...

https://en.wikipedia.org/wiki/Car_platform

 

[Redcap]

A thought as to continued production.

Airframes have a specified maximum number of hours flight time, before they must be completely replaced, or the aircraft grounded permanently. Likewise, engines, avionics, and other parts of an aircraft have life cycles between minor and major maintenance, and ultimate replacement.

If a ship has a 40 year operating life, and it's a design that's going to continue in periodic replacement with the same type over the decades, then there will inevitably be peaks and troughs of production, which suggests to me that Imperial ship building contracts will keep the lines open for civilian sales (if appropriate) between Imperial contracts.

Also, I'm still not following your comment about "Imperial unions"?

 

[mike wightman]

Never think in terms of aircraft for Traveller starships, a better model is the nuclear submarine.

Within the Imperium you have to differentiate between civilian shipyards that can be found at any class A starport and military shipyards which can be on any world regardless of starport type.

I rationalise the construction time thusly:
architect drafts plans
plans are rendered into a computer model
the hull is grown
(I say grown because I view a crystaliron structure as being a single crystal of the iron alloy - this must be allowed to grow in a very carefully controlled manner to avoid flaws using gravitcs, the higher TL superdense and bonded superdense hulls in addition to gravitic technology incorporate nuclear damper technology to manufacture those hulls
drives and ship systems installed.

 

[Redcap]

Never think in terms of aircraft for Traveller starships, a better model is the nuclear submarine.

That makes sense, yes. An almost completely sealed environment, aside from fresh water production; nuclear subs take in sea water, then desalinate and purify it. I'd imagine in a fully closed system (such as the present day IISS, biological liquid waste would be reprocessed into potable water, along with supplies of fresh water from the last port of call; likewise, air would have to be processed, again with top-ups from each port of call along the way (no system will be 100% recyclable, after all).

Within the Imperium you have to differentiate between civilian shipyards that can be found at any class A starport and military shipyards which can be on any world regardless of starport type.

I'd imagine there would be a LOT of ships bought from commercial concerns, such as LSP, GP, et al, much in a similar manner to Newport News, VSEL, and others on present day Earth (for submarines)

I rationalise the construction time thusly:
architect drafts plans
plans are rendered into a computer model
the hull is grown
(I say grown because I view a crystaliron structure as being a single crystal of the iron alloy - this must be allowed to grow in a very carefully controlled manner to avoid flaws using gravitcs, the higher TL superdense and bonded superdense hulls in addition to gravitic technology incorporate nuclear damper technology to manufacture those hulls
drives and ship systems installed.

Hmm. Growing a hull. There's an interesting concept. Have you read "Once a Hero" Elizabeth Moon? There are notes in the story of growing 'filaments', which sound similar to strands of crystaliron, which are remarkably fragile while under growth (and dangerous when fragmented in the zero-g growth environment).

And yes, growing a hull could take time, but my thinking is that it's not the growing of crystaliron that time consuming, it's forming the lattice grid of the rare mineral Lanthanum, that's sandwiched between the layers of hull material that takes the time.

So yes, I can see hulls taking a major slice of time to build, but if production lines are designed to spit out ships for a several hundred or maybe even several thousand ships over the course of a five year contract, I'd imagine that they'd want to make even more profit, so would use that production line to manufacture demilitarised versions of the ship inbetween military contracts, knowing full well that in maybe ten or twenty years, another contract to replace losses would roll in, and all they'd have to do would be to add back in the militarised parts of the production line, and in very short order indeed, out would pop more military ships, and so on.

So, yes, initial runs early on in a contract would take a bit of time, but once the production line was fully established, they'd likely pop out several ships each week or month (depending on production capacity).

 

[mike wightman]

I was studying the material science behind super alloy manufacture for engine turbine blades when it struck me that crystaliron was pretty much a development of such material science.

Growing a single crystal into a starship hull would take time - the gravitics are there to prevent inconsistencies by ensuring a completely zero-g environment for the growth.

 

[Redcap]

I was studying the material science behind super alloy manufacture for engine turbine blades when it struck me that crystaliron was pretty much a development of such material science.

Huh. I know, well, nothing, really, on that score (materials science... and quite a few more topics, actually, dammit!), so I'll take your word for it

Growing a single crystal into a starship hull would take time - the gravitics are there to prevent inconsistencies by ensuring a completely zero-g environment for the growth.

I follow the basic logic there, but I'm not entirely convinced that an entire hull would be grown in one section; several key sections, fitted together like an airframe (or a submarine), perhaps; remember, it's the Lanthanum grid that sends the ship into and out of J-space; the hull is primarily there as protection from micro-meteoroids, reentry, weapons fire, and oh yeah, to keep the biological components (the crew) encased in air, etc.

Hull repairs have to be workable and practicable, and cutting through a hull is a major undertaking; there would therefore likely be an optimum common size of hull plate that forms the jigsaw of pieces that is the hull, and as a result of this, I'd imagine a few common squares of hull material would be in the DC locker in the hold to plug holes up to a metre or two in size.

 

[Condottiere]

I doubt crystaliron is used for the frame and superstructure of commercial spacecraft.

It appears to be an add on option to the hull; you're probably looking at something more plastic, like aluminium, steel, or some form of titanium alloy.

 

[Redcap]

I doubt crystaliron is used for the frame and superstructure of commercial spacecraft.

It appears to be an add on option to the hull; you're probably looking at something more plastic, like aluminium, steel, or some form of titanium alloy.

You're absolutely correct, I likely should have been clearer.

My thinking is that the hull will either bolt onto or be welded/bonded somehow, to the frame of the ship, for ease of replacement, with possibly an airtight inner hull below the lanthanum grid element of the hull, something like a sort of sandwich construction, from the top in this being Crystaliron - Lanthanum grid and conformal former - Inner micrometeoroid shield - Airtight hull - inner working hull surface. Any additional armour that the ship has will normally be in the form of a thicker outer hull surface.

The frame will be similar to that of what one might find in most ocean-going ships currently, with axial and radial frames/grids to maintain structure and form (think about the way aircraft are built as well).

The hull surfaces will be formed of a patchwork of sections, likely as common as possible in size and shape for ease of damage control and replacement, which mate together close to as seamlessly as possible, especially in the case of streamlined vessels.

That's my thinking on it, anyhow.

 

[mike wightman]

I doubt crystaliron is used for the frame and superstructure of commercial spacecraft.

According to the most detailed Traveller ship design systems it is.

It appears to be an add on option to the hull; you're probably looking at something more plastic, like aluminium, steel, or some form of titanium alloy.

Nope, we are talking about the composition of an unarmoured hull itself, and additional armour is likely grown as a thicker hull, you can not can not change the armour rating of a ship during a refit, which you could if it was a bolt on options.

 

[mike wightman]

You're absolutely correct, I likely should have been clearer.

My thinking is that the hull will either bolt onto or be welded/bonded somehow, to the frame of the ship, for ease of replacement, with possibly an airtight inner hull below the lanthanum grid element of the hull, something like a sort of sandwich construction, from the top in this being Crystaliron - Lanthanum grid and conformal former - Inner micrometeoroid shield - Airtight hull - inner working hull surface. Any additional armour that the ship has will normally be in the form of a thicker outer hull surface.

No.
Armour can not be bolted on, refitted or altered except through battle damage. Traveller hulls are as strong as medium tanks before additional armour is designated.

The frame will be similar to that of what one might find in most ocean-going ships currently, with axial and radial frames/grids to maintain structure and form (think about the way aircraft are built as well).

Do not think about aircraft . Traveller ships have bulkheads made out of the same stuff as the hull, its been that way ever since the more detailed description in S7.

A Traveller ship hull, even unarmoured, is the equivalent of a medium tank, with internal bulkheads making up the inner structure, not a frame.

The hull surfaces will be formed of a patchwork of sections, likely as common as possible in size and shape for ease of damage control and replacement, which mate together close to as seamlessly as possible, especially in the case of streamlined vessels.

That's my thinking on it, anyhow.

And every one is a point of weakness which just doesn't appear to be an issue with ships that can easily be still operational after 40 years or more and routinely entering planetary atmospheres etc.as already mentioned.

 

[Condottiere]

Hull costs per tonne would vary, if they used different materials.

Imperium engineers, though, have seemed to have managed to integrate crystatiron or superdense with ferrous nickel.

 

[aramis]

Hull costs per tonne would vary, if they used different materials.

Imperium engineers, though, have seemed to have managed to integrate crystatiron or superdense with ferrous nickel.

Given that the material varies by TL, the standard cost may in fact be the same per ton, provided you're using the standard material for the starport's yard's TL.

 

[Redcap]

According to the most detailed Traveller ship design systems it is.

Which system is that, I wonder?

Nope, we are talking about the composition of an unarmoured hull itself, and additional armour is likely grown as a thicker hull, you can not can not change the armour rating of a ship during a refit, which you could if it was a bolt on options.

I refer the honourable gentleman to Tanks with bolt-on armour (not reactive, but actual plates added as a stand-off armour to defeat HESH rounds).

No.
Armour can not be bolted on, refitted or altered except through battle damage. Traveller hulls are as strong as medium tanks before additional armour is designated.

Please see my comment re bolt-on armour above. I frankly don't see why it's not doable.

Do not think about aircraft . Traveller ships have bulkheads made out of the same stuff as the hull, its been that way ever since the more detailed description in S7.

S7?

A Traveller ship hull, even unarmoured, is the equivalent of a medium tank, with internal bulkheads making up the inner structure, not a frame.

And every one is a point of weakness which just doesn't appear to be an issue with ships that can easily be still operational after 40 years or more and routinely entering planetary atmospheres etc.as already mentioned.

I have to disagree; While I likely don't have the right terms here, not being an engineer, I've seen a fair few diagrams of these things; both aircraft and submarines use radial frames and struts (longitudinal beams, if you will - see how a Hawker Hurricane is designed; the principle appears to be if not the same, certainly similar) to maintain the integrity of the shape of the craft; submarines to withstand immense pressure on the hull at depth, aircraft to hold pressure in at high altitude.

I don't see why starships can't follow the same basic principle?

Hull costs per tonne would vary, if they used different materials.

Imperium engineers, though, have seemed to have managed to integrate crystatiron or superdense with ferrous nickel.

I'm not a metallurgist either, so I'll take your word for it.

However, I fail to see how you can integrate a Lanthanum jump grid into a crystaliron hull while it's growing; hence my thinking that hulls are multi-layer assemblies, made in sections and panels for ease of both construction and maintenance.

 

[flykiller]

imperial unions. "the imperium owns the space between the stars."

Can you expand on this, please, as I'm not sure where you were going with this?

imtu the imperium owns the starports and the starship yards, and also via starship construction unions the skill sets necessary to build starships. it's another layer of control over interstellar traffic and relations.

 

[Grav_Moped]

No.
Armour can not be bolted on, refitted or altered except through battle damage. Traveller hulls are as strong as medium tanks before additional armour is designated.
...

Adding armor to the outside of the hull would increase the ship's displacement and reduce performance.

Adding it to the inside would require disassembly and reconstruction of the entire ship.

Well, that and the rules say you can't.

 

[mike wightman]

Hull costs per tonne would vary, if they used different materials.

They do vary as you will see if you crack open FF&S

Imperium engineers, though, have seemed to have managed to integrate crystatiron or superdense with ferrous nickel.

Evidence from which advanced construction system?

 

[Condottiere]

The Potato.

Now you'll note I mentioned commercial spacecraft, which will take the cheapest viable material to construct the interior and the hull.

As regards military warships, interior bulkheads made of crystaliron or superdense would inherently be stronger for the same volume, and I don't think it's ever been mentioned in High Guard how this translates into extra protection or more hull points.

Failing that, more usable interior volume.


Speaking of which, hard to figure out how you bake in the lanthanum grid into the hull, more attach it to the exterior.

 

[AnotherDilbert]

Which system is that, I wonder?

FF&S, either from TNE or T4.

S7?

CT Supplement 7: Traders and Gunboats.