Building Upright or Upside Down
This is a personal choice. Both have its plus and minus points, but at the end it all boils down to facilities and budgets at hand.
From my personal point of view I prefer to build upside down when possible. However, with some designs you are forced to build the right way up. The v/d Stadt 34 & 40ft frameless hulls comes to mind as it is build inside a building jig, keel down.
Other designs, however, you choose how to go about it.
Here are some pros and cons of both methods.
1. Hull stays in same place until finished
2. No need to hire crane /s to turn over hull when starting the deck
3. Some inside welding done down hand position
1. Strong back is huge and expensive, and frames must hung from this and not easily supported and more difficult to fit, including the keelsom that must be fitted overhead.
2. Plates to be manhandled above and over head, need additional help and is potentially dangerous
3. All outside welds to be done in vertical and overhead position, same with grinding of welds - extremely dangerous to grind above or overhead.
4. Rainwater accumulates in open hull before deck is in place
5. Difficult to remove blasting grid from inside of hull.
BUILDING UPSIDE DOWN
1. Strong back a simple affair and easy to install and support frames onto it.
2. Most plating of hull flat and easy to install and fit
3. Most hull welding and grinding done in down hand position
4. No rainwater accumulates in hull.
5. No grid trapped inside hull when shot blasting
1. Need crane /s or lifting equipment to turn hull over
2. Inside hull welding in overhead position
3. Hull to be leveled after turning over before deck can commences