Only a few things in this world have been given the glory of being pronounced Way Bomb by waybomb. They have to be unique, controversial, enviable, and better than The Bomb.

I officially pronounce rockit man's boat better than the bomb, it is Way Bomb!

I, too, am curious of the Al grade and weld schedule.

Modern motor life boats

47 Motor Life Boat
First built: 1990 (prototype)
Last built: Still in Production
Number built: currently 117;
200 scheduled
Builder: Textron Marine
General Characteristics
Displacement: 40,000 lb (18,000 kg)
Length: 47 ft 11 in (15 m)
Beam: 14 ft (4.3 m)
Draft: 4 ft 6 in (1.4 m)
Hull: 5456 marine aluminium *********
Propulsion: Two 435 hp (324 kW) Detroit Diesel engines
Speed: 25 knots (46 km/h) max; 22 knots (41 km/h) cruise
Range: 200 nautical miles (370 km) cruise
Righting capability: Rollover in under 10 seconds
Complement: 4 crew, 5 passengers
The USCG has since designed and built new aluminum 47 foot lifeboats, with Textron Marine and Land Systems awarded the contract to design and build the US model, which was delivered in 1990. After 2 years of testing and evaluation, 5 more were built between 1992 and 1994 incorporating improvements from the prototype model for further testing and evaluation around the country. The first production boat was delivered to the USCG in 1997.

The 47 MLB is the most sophisticated MLB ever built, able to withstand impacts of three times the acceleration of gravity, she can survive a complete roll-over, self-righting in less than 10 seconds with all machinery remaining fully operational. Powered by twin Detroit Diesels producing 435 hp (324 kW) each, the 47 MLB can travel at 25 knots (46 km/h) to reach her destination.

There are currently 117 operational with a total of 200 scheduled to be delivered to the USCG. A further 27 models are being built by MetalCraft Marine under license to the Canadian Coast Guard.

In Britain, the RNLI designed and built three types of all weather motor lifeboats, the Arun class kept permanently afloat, the Tyne class slipway-launched boat and the Mersey class carriage-launched boat. More recently the Arun replacement Trent and Severn class prototype models were delivered in 1992 with the first production Trent arriving in 1994 and the Severn in 1996. The first production Tamar class, replacement for the Tyne went into service in December 2005 and the FCB2 replacement for the Mersey is being developed for deployment in 2007


Great Job !
I guess the Coast Guard thinks aluminum is strong enough for rescue boats ?
Hey they even use them in salt water!

I asked the welder and the aluminum is 5086
Bottom is.250
Sides is .190
Other parts is a mix
The welder he likes best is a pulse 350

Hope that helps ,you could always call the shop at RiverWild Boats @ 541-955-1970 in Grants Pass Oregon we are listed and have a website though this new boat is not on there yet

Very impressive looking boat! I hope it runs as good as it looks.
Nice work and good luck.

Rockitman..thanks for the updates. You and your son in law are building an awesome project. I am looking forward to seeing this boat someday I commend you on your achievements so far

thanks rockit man that is all i wounted to know . the pulse mig is great it will hold . thanks for the info love your boat robbie .

Rockit man,
What are you going to do about insurance?

"I got this home built aluminum quad step 42 footer with big blocks that shoud run an easy century"...

WELL DONE.
Great lookin, big, flat deck, aluminum deep V offshore. With the exception of 'great lookin', it sounds like Cougar ( no offense to Cougar-types ).

What's not to like ? ? ?
Aluminum, interactive steps, Arnesons ? ? ? . . . yikes. I may be in love.
That's just TOO wicked cool. . . BEST of luck to you.

Awesome, very nice work rockit man!!

What temper, if you don't mind asking. 5086 is a tough, medium-strength Al-Mg alloy suitable for application over the range of temperatures from -452 to 150􀀨F. It ranks among the best in its weldability rating.

However, 5086 should not be used under high constant applied stress for continuous service at temperatures exceeding 150deg F, because of the hazard of developing susceptibility to stress-corrosion cracking. In general, the H34 through H38 tempers of 5086 are not recommended, because these tempers can become susceptible to stress-corrosion cracking.

But as used in a boat, I don't think there's much to worry about as stresses will be intermittent, and temps would generally not be that high - though having said that, I can see occasions where the sun would elevate the deck temps to near 150.


Awesome project, keep us posted.