I've been messing about with Delftship over the past few weeks and have made some more refinements to my hull design. I have been inspired by the Youtube videos of the fast British launches, especially Arlette and Oberon. I have taken some cues from these boats and am targeting that fast launch style, along with adding a bit of a North American flair (Royal C Moore, Fay & Bowen, Joe Walters) with the drake stern.
I have increased the length (over previous iterations) to 26' LOA. I would go longer but I think trailering will become an issue. (also finding a trailer that's not built for a water going motorhome). The drake stern lets me maximize the displacement length to nearly that of the LOA. Beam is 5' at waterline and 5'3" at the gunwale. The target displacement is .95 to 1 ton but I still may need to whittle a bit more off depending on what the machinery weight is looking like. The idea is to be trailerable behind a mid-sized Estate wagon/SUV. I would like to keep the total towing weight under 3500lbs. The model still needs to be refined for shape a bit in the middle and faired, but it's getting pretty close to what I have in my mind eye.
I have also been waffling on the name. I thought I had chosen one but another has been constantly creeping to the top of the list. I guess it doesn't really need to be chosen until the paint goes on, so for now the working name is Idris.
Interesting to see. Is that a hard chine down aft? Was there a reason for limiting its length to 26ft? Might be worth you taking a look at Whio http://aquapx.com/site/#/gallery/whio/p1010951/ 29'6" long, so only slightly longer, and a highly efficent and fast hull. Plans are available if someone is serious, contact me if you are and I'll put you in touch.
Daniel
It is a hard chine aft. I am working on another version with a flatter rise (less v) in the style of many drake stern hulls.
The hull is limited to 26' to keep it reasonable for trailering and launching (and cost, room needed to build & store, etc.). I started this project with an Elliot bay as the target boat which is 23 1/2. The Idris is targeted at a longer length, but with lower displacement and less beam. It won't be quite as fast as the longer Oberon & Arlette but should cut through the water pretty quick. L
The Whio is a pretty boat but much too big. The pics with it lashed up to the Vitara are just plain silly. There is no way that is legally getting on the road in the US. I bet the trailer alone is nearly the towing capacity of the vehicle. The displacement of the Whio is listed just at 3000 lbs, which with a trailer pushes me into a much larger two vehicle.
Hang, on, you are talking 26 feet long but 29'6 is much too big? Whio is not a big boat, is very easy to tow, easier to tow than my 25 foot steam launch which is beamier at the stern due to the counter, and almost twice as heavy.
As for your comments about the Vitara and weights, don't be so totally ridiculous. Check the tow rating and the actual weight of Whio. The fact that it had to only get 500 metres down the road is the reason the Vitara was used, a bigger vehicle is preferable.
Oh, and Whio was originally intended to be steam.
Daniel
marinesteam wrote:
The Whio is a pretty boat but much too big. The pics with it lashed up to the Vitara are just plain silly. There is no way that is legally getting on the road in the US. I bet the trailer alone is nearly the towing capacity of the vehicle. The displacement of the Whio is listed just at 3000 lbs, which with a trailer pushes me into a much larger two vehicle.
Ok, maybe silly was too strong a term to use but the numbers just don't add up and I could never get that rig road legal in the US. A quick check shows Vitara's towing capacity at around two long tons 2645lbs (1200kg) though there is a range but most are significantly less. Trailer weight is probably 1500lbs (680 kg). Even if I subtract 1000lbs from the displacement of Whio for a boat trailering weight of 2000lbs one would still be over the maximum towing capacity by 855 lbs (over by 500lbs for a Grand Vitara). As it sits, most trailers for 29" boats are in the 2000lb range which would be over half of my towing capacity. It's going to be a trick to find a lighter trailer for a 26' boat as they are build to accommodate much heavier hulls than mine. It's possible that the Vitara's available outside the US have larger towing capacities but still your boat (which is a really nice craft) is a lot larger than what I am looking to build.
A Frolic 18 is only six inches longer than my canoe (canadien) but I can't make the argument that the Frolic isn't a much bigger boat. Your boat has a beam of 7.34 feet compared to my target of 5.25. That's a lot off additional volume. The Elliot bay, SF Indian Runner, Bolger launch are all boats that are in my target area, I'm stretching my envelope by quite a bit by going to 26' but the Idris will be somewhat lighter than the three of these, so that helps (and faster). Needless to say another three feet and ton of displacement put it into an entirely different ballpark.
I'd take the Whio in an instant if I had slip space and instant access to a large body of water but in Colorado our water is small and/or distant so trailering (in mountainous terrain) is my reality. And the rest of my reality prevents the purchase of a pickup truck
Cheers
Ken
WHIO MEASUREMENTS
LOA 9.1 m
LWL 8.9 m
BOA 2.24 m
Fuel 120 lt
Displacement 1350 Kg
steamboatjack wrote:Looks like a fast boat! Remember you will need to keep the steam plant as light as possible to achieve this sort of displacement.
Regards Jack
Yes, It's going to be a squeeze.
Arlette is listed as having a side-fired locomotive boiler and a single. Oberon has a water-tube and compound that is roughly the same size as the York I am building, though probably lighter. My target weight is more along that of Arlette at 1 ton opposed to the .9 of Oberon. I need start looking at boiler design more seriously to get a handle on what that part of the weight budget looks like. It's going to be a bit of a compromise and I don't expect to get quite the speed from Idris as with the longer hulls but she should still be fast.
In BC Canada, any trailer weight and load over 2800 lb requires brakes on the trailer. I question whether to towing capicities rated by the car manufactures are just a cop-out for them! You may not go but you better be able to STOP!! I have disc brakes on my trailer ,axles rated for 6000 lb each [two] and it handles great.I first started with a 150 Ford and when it wore out ,switched to a Ram 3500 [/img] [/img]
farmerden wrote:In BC Canada, any trailer weight and load over 2800 lb requires brakes on the trailer. I question whether to towing capicities rated by the car manufactures are just a cop-out for them! You may not go but you better be able to STOP!! I have disc brakes on my trailer ,axles rated for 6000 lb each [two] and it handles great.I first started with a 150 Ford and when it wore out ,switched to a Ram 3500
The towing capacity is determined by the weakest link in the chain. Two autos with different hp rated engines, but otherwise identical often have the same tow capacity. Transmission and brakes do play a role as does cooling and vehicle weight.
The problem that I am seeing is that trailer manufacturers build for big cabin cruiser style boats with trailer weights increased accordingly. Long, light boats need not apply. I will have to find a manufacturer that will do an extended trailer with a lower weight capacity to keep the trailer weight down as well. If I can I will spec brakes even if not required as it will take some of the strain off of the tow vehicle in the mountains.
