There's a bit of a difference between a forgeworld produced 10m land raider being modified in a vehicle workshop and constructing a 5km starship from scratch. Even if they had the technical knowledge, they'd have neither the manpower, resources or facilities required.
Stone aged tribesmen managed to mine enough metal to build the
Lord Daros in 11 years. One would imagine that a SM chapter could build a smaller ship faster. And, again, fluff states that SM do have the facilities to make their own ships. This is not a 'Well maybe...' issue, fluff is clear on this subject (for once). Both Dark Angels (another fleet based chapter) and Ultramarines are stated, not in a suggestive sort of maybe manner, but clearly(!) to have their own production facilities manned by chapter serfs.
As far as how such a facility might work in a chapter fleet, I'll use the provinder ship
Bountiful Beast as an example. The
Beast is 16 km long, having a volume 111 times that of a strike cruiser, and is of a hull class frequently used in Imperial Crusades as a mass conveyance of victuals, according to fluff (yes, this makes it twice the length of an Emperor class battleship, but those are it's canon stats). One would not have a hard time imagining a hull this size made into a mobile dockyard for cruisers and escorts.
And again, we're looking at just replacing ships lost to attrition, not building a fleet from scratch.
@D'Art
BT fluff from
Games Workshop. You know, the font of all official fluff? Pick up a copy of something called
Codex: Black Templars. Very interesting stuff in the fluff section at the beginning of the book.
Oh, and there was a BT fleet list once upon a time from Ray. Not official, but interesting enough.
The Land Raider Crusader was not just a weapon refit of the existing landraider, as it also has expanded troop carrying ability, which implies extensive internal reconfigurations.
As far as that reactor goes, it depends on where the hole is if all it needs is some fast welding. However, most things beyond that, as I stated before, will need some knowledge of how it actually works to fix it, even with a quick and dirty repair, particularly nukes (See K-19). Hell, anything electronic, or even some just electrical things, you WILL need to know how it works to fix it, even a quick and dirty repair.
@Sig: And yet, they do!
Again, this is EXACTLY what it states in fluff:
"Although utterly loyal to the Emperor, the Black Templars are at the extreme end of Independence from Imperial authorities, verging on a rogue element. Their fleet based nature and the goals of their 10,000 year crusade take the Black Templars throughout the galaxy, and it is primarily the will of their Marshals that send them to war. Like all Space Marines, they do not consider themselves subject to Imperial rule, and each Crusade is effectively an autonomous fighting force, though they may choose to respond to requests for aid made by others in their vicinity (as happened during the Armageddon Crusade)." -
Codex: Black Templars, pg 9.
And, I might point out, the problem you are having is right there: 40k HAS no internal consistency since GW changes fluff every new edition of 40k that comes out. Black Templars approach the old legions in size, by some estimates, and would require ships and equipment comparable to that to get around.
And, bluntly, you have not offered up any fluff proof at all of your position other then the oddly worded entry in Armada and your interpretation of another. I've produced excerpts from a dozen sources so far, all published by GW that support my position.