I kind of refrained from commenting on this thread to not make it larger and contribute to it. Even though "Pipe Wrench is Satan.", I would have to agree with the opinions of people who use pipe wrench EXCLUSIVELY on their gunner rather than a spanner even for situational usage. Which is why I don't think this thread should even exist... sorry Fred.
As have been said before, on components such as main engines, light guns and heavy guns(the components usually maintained by gunners), while rebuilding alone, a pipe wrench is not that "out-classed" by the spanner in rebuild power and time. The difference in time of rebuild with spanner and pipe wrench, calculated from game code variables and delays is about 1.6 seconds on average between all those 3 components(ofc latency and game processing comes into effect which might make it scale a tad.).
The amount of time you gain from faster rebuilding with the spanner is far lower than the amount of time and mental capacity you lose while fully repairing the gun/engine back up. It is simply not worth it nor was it ever been, to grab a spanner - other than filling your desire of achievements because Muse doesn't like to update achievements to the 21st century.
The more I think about it, the more I believe the spanner may be the correct choice on the Goldfish. The lifeblood of the goldfish is getting that heavy gun up when it is disabled, and speeding that process up would be great. I do think it is reasonable to believe that an engineer will be nearby at all times. After all, even if both engis are at the back, it just takes one quick sprint to get there, and they can also fix the hull while they are there. I'm not convinced it is good on any of the other ships though.
I have mained on a fish long enough to know that a good fish will have the main engineer running around to the engines, side guns, and even balloon way too much to babysit the front gun. Sure, it's up there on the priority list, but there are a lot of things that can and will come before it to make the ship more adept.
Not to mention that when going to the engines, and the balloon engineer is busy with balloon, the front gunner is the only one able to quickly respond to hull HP decreasing rapidly, and to be able to efficiently make sure the armor survives longer it is simply not possible to give the gunner a spanner. No matter how much I curse the front gunner for pipe-wrenching the armor a second before I arrive making it gain less HP and the cooldown kills it, there will still be triple as many times as that scenario where the pipe wrench actually saves the armor.