Welding the skin to the frames demystified

[MikeJohns]

You can calculate shrinkage quite accurately too and actually incorporate it into the panel, any shipbuilder has to take this into account and it also drives the welding schedule of what gets welded to what where and when.

In the last days of rivetted vessels the plating was welded on the butts (the vertical plate joins) and riveted on overlapping longitudinal seams and riveted to the transverse frames, many of these boats were incredibly fair (and still are). But welding is much more precise afair these days and consistent shrinkage with MIG processes and a reasonable welder can produce welded vessels with very low distortion.

In a good shipyard you will find masters of line heating that can flatten or curve a sheet of steel with surprising accuaracy.

[Guest62110524]

Originally Posted by MikeJohns

You can calculate shrinkage quite accurately too and actually incorporate it into the panel, any shipbuilder has to take this into account and it also drives the welding schedule of what gets welded to what where and when.

In the last days of rivetted vessels the plating was welded on the butts (the vertical plate joins) and riveted on overlapping longitudinal seams and riveted to the transverse frames, many of these boats were incredibly fair (and still are). But welding is much more precise afair these days and consistent shrinkage with MIG processes and a reasonable welder can produce welded vessels with very low distortion.

In a good shipyard you will find masters of line heating that can flatten or curve a sheet of steel with surprising accuaracy.

i learnt to shrink when I was 13, do not scoff, I worked sweeping floors in an old fashioned panel beaters shop
they would get me to heat, a penny sized spot , and then quench
Later in life, when I was steelbuilding, I used this techique when getting rid of a BUBBLE in a plate
The Dutch covered the decks wet straw for shrinking
Of course in those days as a beginner, I did not have stretching and forming gear, so often my plates got too wide, hence the need for the shrink
i have seen beautifully fair rivetted ships, and I watch these silly welding threads with amazement, just imagine an old time shipbuilder reading this stuff, and stuff abt arc strikes, which goes on and on and on, ) come on!!!