Construction started on May 5 2002. Launched on Aug 5 2003. Finally got my new wave piercing long range power cat wet. 15 months to the day of part time construction. It was hauled from the build shed last week with the hulls and connecting struts loaded by crane on a flat bed and taken to a marina. The cabin, a 11'8" wide load was taken by a smaller flat bed to the marina and picked up by their travel lift. After a bit of fiddling all 60 bolts fell into place and were nutted up so the travel lift could go away.
I spent the next few days hooking up the drive train belts and the cooling connections as well as putting some fuel in the main tanks and finishing the pumps filters and plumbing to the day tank. Suffice to say that once the 'ins' and 'outs' corresponded to the direction of fuel flow I was able to put 5 gallons into the day tank :)
I bravely put some masking tape on the bottom at expected waterline given the fact the front tanks were empty ( 1500 lbs ) and we dropped her in.
The front tape was right on the mark but the stern was about 4" under.
Spun up the engine and thrust from the jet drives was immediately apparent at idle. An quick kick on startup as she surged forward on her lines. A few minutes later the port bilge pump came on and continues to do so every few minutes. Looks like the P.S.S. seal on that shaft will need adjustment. Tried out the reverse controls as I had some serious concern about being able to get into reverse with the push/pull against the jet wash and in particular to be able to get out given the pivot geometry. Was able to get in and out at idle no problem. However the full reverse position was not achieved with just a mild reverse effect.
Tested the engine up to around 1700 RPM but got some toothed belt drive jump. Lots off thrust at that RPM.
The leak was not getting worse and the engine reliably happy to 1500 so we started down the narrow channel between the docks on the way to her home berth. Had a couple of guys with pike poles on the hulls but not needed as we headed up the channel. Speed at 750 RPM was just over 3kn. Steering via the single jet nozzle was predictable but not strong. Did a hard turn to starboard with reverse on the starboard drive as we left the marina and entered the main channel. Throttled up to 1000 RPM and eventually to 1200 where we made about 5.7kn on the GPS. There should have been a weak current against us. The predicted speed at 1200 RPM was 5.2 -> 6.3 kn depending on what her propeller factor Nx actually is .. see performance estimates at http://www.mala.bc.ca/~bigras/o8/o8perf.htm so it looks like she is in there somewhere.
Did a few more low speed turns in front of her marina with the reverse buckets and throttled up a bit with them in reverse then headed in to the slip. It has an easy approach but the guys with the poles got to help when I failed to get reverse on the starboard drive. This was due to the steering not being near centered so the nozzle gets in the way of the bucket as expected but forgotten in the moment. Basically low speed turns should be done just with forward and reverse and not the high speed steering nozzle.
Tied up and had some bubbly.
The shaft seal with require a access hatch cut in the aft deck. This then screwed down and bedded in 4200 until the next time I need to get in there. Will make the same hatch in for the starboard side as well though no problem there currently.
The belt drives will need further tension adjustment and also some additional cross brace on the jack shaft frame and I will test that to 3000 RPM before she next goes out.
As well some tuning of the reverse buckets will be needed.
The biggest issue is that it would seem that about 600 lbs have somehow snuck into the boat during construction .... most of it aft. This will require a small design modification before any serious offshore work with a bit a of a double bottom aft likely. No problem for now or trips and sea trials in local waters.
The shaft leak has been fixed and an interim solution for the reverse has been found. May end up permanent... Construction of a double bottom is underway to add the additional bouyancy required.
A tight fit for the starboard hull as it is rolled out.
Out the door waiting for the crane.
Off goes the first one. Usual need to moderate crane operator enthusiasm.
And the second. The aft deck was also taken on this truck.
Cabin was a wide load taken on a small flatbed.
Picking up the cabin from the flatbed with a travelift.
Putting the cabin in place at the marina.
Fiddling to get all 60 bolts in place at the same time. Getting it all level was the key.
Fuel tanks painted and new vent pipes to replace the one that got busted during assembly.
The beast awaits her launch. Note the international orange underbelly.
During engine testing pumped a pint of diesel into the cabin. The daytank fill valve had been left open and it is 'T'ed in with the return line....
Quarter view.
Travelift picks up. The fenders are water toy 'noodles'. Running the length of the flat part they should work better than conventional fenders.
Heading over the water.
Getting wet for the very first time.
Made it to the other marina.
Hanging out with her new pals.
She is overweight by about 600 lbs. Bow trim is as expected with current tankage and load but she is trimed down about 4" below what was expected at the stern. She will require a stern lift :)
In the yard, you can see the bouyancy false bottom additions. Didn't get much of a break for storing the owners fish boat between the hulls.
When the thrust bearing had slipped she only got 1700RPM. With it fixed 2000 in static testing. This is around 1400 RPM.
Pretty picture of static testing around 1400RPM.
Underway at 8kn, 1650RPM . Very small wave train. Burned 4 litres diesel in about 11 kn miles.
The bow at 8kn. Max RPM was 2200 with about 9.4kn so additional gear reduction is needed. Will change down a sprocket on the jack shaft.
Putting along at about 4kn. Yellow things are 'noodle' fenders.
At 8kn.
A bit closer. The bow is trimmed up a couple of inches but the stern is not trimmed down. Likely an effect of the wedge shaped additional bouyancy.
Copyright © 2003 Tony Bigras.