Early US SWATH vessel name ???

[DCockey]

Does anyone recall the name of a SWATH vessel which was built for the US Navy in the 1970's? My recollection is it was built for the US Navy or US Coast Guard as a proof of concept but was nominally a harbor patrol vessel or similar due to funding issues.

 

[jehardiman]

Kaimalino

 

[Ad Hoc]

You may find THIS of interest too.

 

[jehardiman]

And if you want info on Kaimalino's design look up the Hydrodynamic Design of a S3 Semi-submerged Ship, Lang, Ninth Symposium: Naval Hydrodynamic, Volume 1, Unconventional Ships and Ocean Engineering, Paris 1972, ONR/ACR - 203

 

[DCockey]

Thanks for the name and video link. I first heard of Kaimalino at the 1979 AIAA/SNAME Advanced Marine Vessel conference in Baltimore. Around 10 years later while living in Rochester Hills, Michigan I watched a video about Kaimalino (possibly the one Ad Hoc linked to) on the community TV channel. I don't recall the details of the link to Rochester Hills but I recall someone who had worked on it, possibly as a contractor, had relocated to Rochester Hills. Today I saw a reference to the US Navy's "first SWATH vessel" but it was about the first commissioned SWATH vessel. Correction - the vessel I saw a reference to was not commissioned.

 

[Ad Hoc]

... Today I saw a reference to the US Navy's "first SWATH vessel" but it was about the first commissioned SWATH vessel.

Are you referring to the Halcyon Offshore Support Vessel?

 

[DCockey]

Are you referring to the Halcyon Offshore Support Vessel?

The reference I saw was in an announcement for a SNAME webinar by Barry Tibbetts:

T-AGOS 19 (USNS Victorious) was the lead ship in a class of special mission ships designed during the peak of the Cold War. The need was urgent so only eight months were available for the design, followed by competitively selecting the shipbuilder in only six months. It was also the Navy’s first SWATH (small waterplane area twin hull) ship. Being the first, there were many technical challenges, little time to resolve them, and none of the design tools had been validated full scale. ​

 

[Ad Hoc]

...T-AGOS 19 (USNS Victorious) ..

Doh!!.. of course, totally slipped my mind on those T-Agos 19-23

Nice image HERE too.

 

[jehardiman]

Are you referring to the Halcyon Offshore Support Vessel?

You mean Duplus in 1969? She was converted to a cat soon after launch due to poor performance....all the real research was done 1967-72 down at the OMB in Escondido (don't make me drag out my references). Kaimalino (circa 1972) was really the first competent SWATH. And USS Victorious (T-AGOS-19 circa 1985) the first main fleet unit (CCGS FREDERICK G. CREED (circa 1987) doesn't really count, she was built as a spectator boat for the 1988 AC but couldn't make spec).

Edit: X-post while digging out my senior design project....

 

[Ad Hoc]

You mean Duplus in 1969?...

No the Halcyon - see attached poorly scanned in ...also written about by QM Lewis in 1985. at SNAME meeting.

 

[jehardiman]

The reference I saw was in an announcement for a SNAME webinar by Barry Tibbetts:

T-AGOS 19 (USNS Victorious) was the lead ship in a class of special mission ships designed during the peak of the Cold War. The need was urgent so only eight months were available for the design, followed by competitively selecting the shipbuilder in only six months. It was also the Navy’s first SWATH (small waterplane area twin hull) ship. Being the first, there were many technical challenges, little time to resolve them, and none of the design tools had been validated full scale. ​

When I presented my senior design project at UofM, May 1984, 2 MSC managers and a shipbuilder were there...My design and T-AGOS-19 were almost exact copies....It's what the data pushed you to, as I have said before, there are only 3 sizes of SAWTHs...

 

[jehardiman]

No the Halcyon - see attached poorly scanned in ...also written about by QM Lewis in 1985. at SNAME meeting.

All the small SWATHs at that time were failures, you can't build the crossdeck/strut joint strong enough without dropping the crossdeck too low and having slamming issues. Lots of cracking and overweight issues.

 

[Ad Hoc]

All the small SWATHs at that time were failures, you can't build the crossdeck/strut joint strong enough without dropping the crossdeck too low and having slamming issues. Lots of cracking and overweight issues.

I beg to differ.
It is all about identifying the load paths and applying appropriate fatigue values to the main areas of concern.

 

[kleenbreeze]

Does anyone recall the name of a SWATH vessel which was built for the US Navy in the 1970's? My recollection is it was built for the US Navy or US Coast Guard as a proof of concept but was nominally a harbor patrol vessel or similar due to funding issues.

Don't recall it's name but have seen it docked in Point Loma naval base, it is probably still there. Last time I saw it one hull was partially submerged and it was listing badly.

 

[Ad Hoc]

David

You may be interested to watch the webinar on the T-AGOS 19 tomorrow, noted HERE.