Cut and weld,,,,,,,,,,,,full size!!

[Rheged]

I know we as a community sometimes do a "cut and weld" job to amend or extend a model.  The French are doing it at 1/1 scale with submarines!

https://www.msn.com/en-gb/news/world/two-french-submarines-are-cut-in-half-to-make-new-working-sub/ar-BB1fG5Lx?ocid=msedgntp

And before you look on this as unique, look at replacing the bow of the USS San Francisco with the bow of the USS Honolulu, or even marrying up parts of HMS Zulu and HMS Nubian to produce HMS Zubian!!   
   
https://en.wikipedia.org/wiki/HMS_Zubian

[kerick]

Not nearly as complicated but a section of the bow of the USS Kentucky was used to replace the damaged portion of the bow of the USS Wisconsin. IIRC this made the Wisconsin slightly longer than the rest of the Iowa class.

[scooter]

And cruise lines do this regularly with their block of flats on a barge that are mistakenly called a "ship", when they want to add even *more* capacity.

[PR19_Kit]

It's quite a common process in the ferry and cruise liner world too.

Probably Britain's most famous ferry, the  MV Norland which carried many of the troops to the Falklands in 1982, was lengthened after she returned from 'down south', by cutting her in half and welding in a 20 mtr length.

I spent many a happy hour aboard the Norland, yo-yoing back and forth between Hull and Rotterdam in the 80s, a lovely ship indeed. 

[kerick]

One thing about a submarine is you better get all those welds right!

[Rick Lowe]

One thing about a submarine is you better get all those welds right!

And cruise lines ... with their block of flats on a barge that are mistakenly called a "ship" ...

Well put.

[crudebuteffective]

One thing about a submarine is you better get all those welds right!

not a job for the apprentice

[Nick]

One thing about a submarine is you better get all those welds right!

not a job for the apprentice

Certainly not the team who built HMS Triumph in the 80s. They put the entire submarine bow on upside down 

Marshalls did a good job on extending the C-130 fuselages by putting in 2 separate sections each side of the wing.

[PR19_Kit]

Marshalls did a good job on extending the C-130 fuselages by putting in 2 separate sections each side of the wing.

And cutting HUGE holes in the side of the fuselages of the RAF's Tri-Stars for the cargo hatch. 

The test rig for that job was mind bogglingly complicated, considering that Lockheed's version of the same rig was about  1/3 of the size.