Most buoyant 1.25m part?

[HafCoJoe]

I'm curious what the best 1.25m part is for making a floating craft? I need to know as I'm making a rather large, load bearing catamaran to send to Laythe.

[Jarin]

2 minutes ago, Avera9eJoe said:

I'm curious what the best 1.25m part is for making a floating craft? I need to know as I'm making a rather large, load bearing catamaran to send to Laythe.

Empty fuel tanks, I'm pretty sure. But honestly, your typical problem is not floating, but sinking. Just about everything floats, to the point where negative buoyancy is rather difficult to achieve.

[Ultimate Steve]

Yes, as @Jarin said pretty much everything floats. The only things that really sink are full ore tanks and girders.

[HafCoJoe]

Aye I know that empty fuel tanks are great  I'm curious if there are genuinely some that are better than others? I'm hoisting a lot of weight and it's going to be above the water, rather than sitting on it, and it's going to be moving fast. Looking for the best way to reduce drag and increase lift with the given parts. I was using the large SRBs as pontoons before. Is that a good plan in your eyes?

[Cunjo Carl]

@Avera9eJoe . Sounds like a fun trip. Here's a spreadsheet started by @Pds314 in this thread which shows the bouyancy of some of the more exciting parts. It was made in 1.1, but I believe besides a couple engines, relatively few parts have changed mass since then. I've used the spreadsheet a half-dozen times for similar design decisions, and hope it works well for you, too!

It's set to edit mode, so please be careful not to change anything unintentionally!

I'll also take a gander through the parts list later this evening and see if there's any hidden treasures.

Good luck, and happy sailing.

Edited April 5, 2017 by Cunjo Carl

[Jarin]

49 minutes ago, Cunjo Carl said:

@Avera9eJoe . Sounds like a fun trip. Here's a spreadsheet started by @Pds314 in this thread which shows the bouyancy of some of the more exciting parts. It was made in 1.1, but I believe besides a couple engines, relatively few parts have changed mass since then. I've used the spreadsheet dozens of times for similar design decisions, and hope it works well for you, too!

Am I blind, or does that spreadsheet not have 1.25m or 2.5m fuel tanks at all? 

Wonderfully useful otherwise though. Looks like structural fuselages might be the way to go for a proper pontoon. Wouldn't have called that one, with the open ends, but it seems like it's a rough model anyway.

[Cunjo Carl]

2 hours ago, Jarin said:

Am I blind, or does that spreadsheet not have 1.25m or 2.5m fuel tanks at all? 

Wonderfully useful otherwise though. Looks like structural fuselages might be the way to go for a proper pontoon. Wouldn't have called that one, with the open ends, but it seems like it's a rough model anyway.

Absolutely not in there at all. I'm about to fix that in 10 minutes though . Structural fuselages are pretty standard for this roll, but I'm hoping there will be another thing that pops out when I start poking around.

 

Edit: The results are in! The structural fuselage has always been the part to beat for 1.25m floatation, and it was a tough bar to beat! The best float for the mass was a closed klaw. Unfortunately, they only have one attachment node and they're very draggy, so perhaps not of much use for a katamaran.

Along those lines, the big strakes didn't come in that far behind the structural fuselage, and they're very low drag (they use the lifting surface model rather than the drag cube model). They also reenter more easily than fuel tanks or structural fuselages. I might give those a look!

The mk1 diverterless intake and mk1 engine nacelles also had floatation/mass similar to the structural fuselage, but substantially better float/length. If you wanted a shorter hull with more stuff on it.

The most important collumns are the mass, and the EW/mass, which describes how many tons a single ton of that item can hold afloat.

Again, best of luck @Avera9eJoe! Let me know if there's any other parts in specific you'd like tested and take care on the journey to Laythe. The last step is a doozie!

Edited April 5, 2017 by Cunjo Carl

[HafCoJoe]

4 hours ago, Cunjo Carl said:

Absolutely not in there at all. I'm about to fix that in 10 minutes though . Structural fuselages are pretty standard for this roll, but I'm hoping there will be another thing that pops out when I start poking around.

 

Edit: The results are in! The structural fuselage has always been the part to beat for 1.25m floatation, and it was a tough bar to beat! The best float for the mass was a closed klaw. Unfortunately, they only have one attachment node and they're very draggy, so perhaps not of much use for a katamaran.

Along those lines, the big strakes didn't come in that far behind the structural fuselage, and they're very low drag (they use the lifting surface model rather than the drag cube model). They also reenter more easily than fuel tanks or structural fuselages. I might give those a look!

The mk1 diverterless intake and mk1 engine nacelles also had floatation/mass similar to the structural fuselage, but substantially better float/length. If you wanted a shorter hull with more stuff on it.

The most important collumns are the mass, and the EW/mass, which describes how many tons a single ton of that item can hold afloat.

Again, best of luck @Avera9eJoe! Let me know if there's any other parts in specific you'd like tested and take care on the journey to Laythe. The last step is a doozie!

Dear God that is amazing... thank you so much Cunjo! That is exactly what I needed  So the bigger the negative in the EW/mass column the 'better'? I.E. the Structural Fuselage is awesome?

EDIT: And since you seem to take interest in my mission, I'll link you a stream I did working on the mission last week. 23min - Project Ambition - I did a quick paint.net demo before the stream and it should describe the kind of boat I'm making. A bit unorthodox

Edited April 5, 2017 by Avera9eJoe

[fourfa]

15 hours ago, Ultimate Steve said:

Yes, as @Jarin said pretty much everything floats. The only things that really sink are full ore tanks and girders.

Vector engines beat ore and girders handily as ballast, actually