Torpedo bulges changes

[janxol]

Brainstorming through some of my designs i have come to the realization that I never - ever - decide to add bulges to the ship. Upon giving it more thought I came to the conclusion that the issue stems from the in-game representation of bulging.

As is, torpedo bulges - just to clarify I mean the actual bulging, not the TDS - add 500 tons of displacement and reduce speed by 10%, which is typically 2-3 knots. Which is a lot, considering that a ship needing bulges will typically need every knot of speed as well, as - at least in my case - these tend to be aging battleships. In which case 2 knots is more valuable than the bulge. The core of the issue is different however.

No matter the size of the ship*, the bulge is 500 tons and costs 10% speed. A 5 000 ton 28 knot cruiser would gain 500 tons and lose 3 knots. An 80 000 ton 28 knot battleship would also gain 500 tons and lose 3 knots. And that just doesnt seem right, does it? Additionally, while in case of this example cruiser it might be possible to do engine refit to gain the speed back using those 500 tons and technology gap, it is unlikely to be possible on this example battleship.

I can see two solutions to this. Either:

1. Keep linear speed reduction, but scale the size of the bulge to the size of the ship. This would mean that for 80 000 ton battleship in question the bulge would be much larger than the bulge on our cruiser, possibly allowing for use of this weight to re-engine. Thew downside would be difficulty of keeping track of maximum tonnage of the ship when approaching 90 000 ton limit or when trying to fit into certain class restrictions, like CVL for example.

2. Keep the size of 500 tons but scale the speed loss to the size of the ship. Applying a 500 ton bulge to a large ship will mean it is not extruding as much compared to the original beam. The increase in drag would be proportionately lower than applying the same displacement of bulge to a smaller - shorter and narrower - ship. The small ship should lose more speed than the large one, possibly a lot more than 10% in case of particularly small ships (HMS Glatton had sizeable bulges, which resulted in loss of 2 knots from 14 down to 12, at 5 746 tons displacement with the bulge) but I find it hard to believe USS Iowa would lose 3 knots of speed when presented with a 500 ton bulge.

*I have never attempted to bulge a ship below 5000 tons, so if something changes below that, I don't know about it.

[ludovic]

The reason I never get torpedo bulges is because the speed penalty is applied after the inherent hull speed limitation. I.e. if you have an old hull that has a maximum speed of 23, if you apply bulges and do an engine rebuild, the maximum speed you can give it is still 23, which will then be reduced to 21 after the bulges, which is never fast enough to keep up with the fleet by the time I want to do a refit.

The bulge, however, if it is kept at 500 tons, would be a "must have" for very old ships if I'm doing an engine rebuild, because you can use the 500 tons to then further increase your speed back up the hull max. If the hull speed max takes into account the penalty for bulges, but starts at something more like 350 tons for a 10000 ton ship and then scales up per your suggestion for larger hulls, then I would have to think about whether I wanted it or not rather than always getting it or not getting it.

[stww2]

Bulges work pretty well on BC to CV conversions, since BC's are usually fast enough to begin with that even without replacing the machinery you'll still get a relatively fast carrier (at least for the early years). I do like the idea of bulges scaling based off of ship size...it does seem rather odd that the bulge for a 10,000 ton ship would add the same number of tons at a 35,000 ton ship.