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ContinuousWave: Post-Classic Whalers
Trailer for 1993 21 Walkaround.
|Author||Topic: Trailer for 1993 21 Walkaround.|
posted 02-28-2012 05:58 PM ET (US)
[Seeks] recommendations for a trailer for [a 1993 Boston Whaler 21 WALKAROUND]. A link to a photo of a similar model on the trailer recommended would be helpful. Thanks.
posted 02-28-2012 07:54 PM ET (US)
Jessie--David Hart "Hoosier" on the board has a 21 and has been working with his existing trailer to get it to fit his 21 Walkaround. Just like the 23 Walkaround, the 21' hull has a good bit of taper to it in plan view from bow to stern as well as in side profile. This makes is tough to get an off the shelf trailer to fit it right out of the box. It can be done with a good bit of work.
Here are a few images of our trailer for our 23 Walkaround Whaler Drive which shows how the bunks were done to accommodate for this hull. From the front of the bunks to the back of the bunks there is a 12" change, narrowing in at the back. Also when there is about a 7" difference in the height on the bunks from the front to back. On the 23 the bow V is actually almost 12" deeper than it is at the stern.
You can see the bunk taper in these images. The I-Beams are parallel to each other.
Our trailer was custom built by Boatwheels in Lorain Ohio. We took the boat down there and they built the trailer around the hull. The trailer is a 9500 or 10,000 capacity trailer and has a number of upgrades (Kodiak brakes on both axles, 6 lug hubs, etc, etc). It was about $4,500. A Helluva deal especially for a custom built trailer. Here are other images.
posted 02-28-2012 07:57 PM ET (US)
Here is link to BoatWheels website.
|L H G||
posted 02-29-2012 01:54 AM ET (US)
Jeff - My background in Design and Structural Engineering leaves me with two concerns I see on your Dad's trailer.
There is no keel/transom support at the center of the back crossmember for the considerable loading from the twin setback engines and heavy Saltshaker bracket. I think large twin engine Whalers need some transom support there at centerline of the keel. The bunks are pretty far outboard, and the transom wood may not even be on them. Keel rollers or closely vee-d interior bunks could do the job.
In addition, I don't like the engineering on that back crossmember. Looking at the trailer configuration, it is carrying almost half the total load of the boat, and is only hung off one FLANGE of an aluminum I-beam, with only one 1/2" U-bolt on each side, with about 2000# on each connection, all the while under continuous flex loading while the boat moves down the highway. The flanges of an aluminum I-beam, with nowhere near the strength of structual steel I or Channel sections, are not meant for that kind of concentrated offset loading and are likely to twist and deform. On any I-beam section, the flanges are only meant to be tension or compression members. I would look into that situation to better transfer the loading from the crossmember to the main I-beam frame.
posted 02-29-2012 11:53 AM ET (US)
Lets be clear that your "background in Design and Structural Engineering" is in Architecture and not chassis design and vehicle systems. My father has worked for 30+ years in vehicle engineering and design. From the late eighties through he retirement in the early 2000's he was the person put in charge of taking a designer's sketch and figuring out how to design and a build a fully functioning, drivable vehicle. In fact all the Cadillac concept cars from that time were his. Even in retirement he still designs and builds today. He worked with the builders when the trailer was being concepted and approved the detailing it for production based on his real word knowledge and first hand experience. He even consulted with members of his current chassis design team on certain details. I am very comfortable in saying there is little, if any need for concern about the trailer's structural integrity.
As for the trailer and it's support. Just looking at images of the hull you may think you know what it needs. When the boat was actually inspected and weighed to figure out center of gravity so the support system could be designed for the hull, it was found that to get the boat to sit correctly on the trailer the majority of the weight ends up much farther forward than we thought. This puts the keel much lower than the stern and why the trailer was designed to have the forward keel bunks carry much more of the load than you might think. The rear bunks are designed to support the hull from the lifting strake. This was done because the major longitudinal bulkheads run in line with those lifting strakes. The hull actually sits on this trailer bunk with the bottom of strake sitting on the top surface of the bunk hold downward forces and the fileted edge and hull side carrying a bit of side load. The bunks stay in contact with these areas from start to finish which required a great bit of shaping on the bunks which is not evident until you see it in person.
Here is an illustration of how the keel rises as on our trailer.
Cross section illustration of the lifting strake in relation to the longitudinal bulkhead
Illustration of how the bunk supports the strake
Larry, each of us look at things differently. For me, there is never one right way to solve a problem. While you may be happy with your off-the-shelf upgraded Continental trailers hauling your Classic hulls that does not mean that that type of trailer setup will work for a Post Classic hull. My experience in having a Post Classic Whaler has been there challenges you face in fitting a trailer to one of these hulls. Especially the Van Lancker designed 21 and 23 hull. While it might not say Continental on the trailer I do believe our trailer is the right one for our hull. It had a lot of thought and planning that went into building it from scratch correctly from the start; instead of buying an off the shelf trailer and altering it heavily to make it work well.
|L H G||
posted 02-29-2012 03:41 PM ET (US)
You're welcome, Jeff.
posted 02-29-2012 04:06 PM ET (US)
Jeff - As you may know, I recently purchased a new boat which came an aluminum trailer that is very similar to the trailer shown in your pictures. I'm not an engineer, but I fear that my trailer's cross-members and flanges may be unduly stressed, and I would hate to have my trailer fall apart while traveling down the highway.
I noticed in your post that you mentioned Continental trailers. Although I'm having trouble recalling the source, I'm virtually certain that I've heard people extoll Continental trailers as perhaps the best trailers ever built, particular the galvanized steel models with keel rollers. You know how it is - I don't know who "they" are, but "they" sure seem to know what they're talking about. Can you provide me any leads on where to obtain a Continental trailer and how to set one up in an aesthetically-pleasing, architecturally-sound manner?
posted 02-29-2012 06:03 PM ET (US)
Thanks for the detailed look at your trailer setup. The design illustrations and photos of the finished trailer clearly indicate this is indeed a tough hull form to correctly fit to a trailer and best suited to the custom market.
How much bow drop do you experience when launching / loading on a typically angled ramp? This is the only drawback I can see in the design of your trailer, but it is obviously corrected for by the low double winch stand. I think you definitely got your money's worth at that price.
posted 02-29-2012 06:34 PM ET (US)
Cross Country Boat Transport. This is the company my father and I started in the 80s. Call them they will take care of you.
|L H G||
posted 02-29-2012 07:07 PM ET (US)
John - I think you fell for Kevin's attempt to make fun of me, but nevertheless, I bought this trailer that carries my recent Montauk purchase from Cross Country. They were first class people to deal with and the price was excellent at $1100. I did not realize that you had started the Company.
posted 02-29-2012 08:50 PM ET (US)
Jessie, here's the short answer that I got from Mid West Manufacturing, who makes Shoreland'r trailers.
"In 1994 the 21’ Boston Whaler Outrage was matched up with the 2146T. The current trailer model with rollers will be the SLR46TBS ."
As discussed above, getting the boat off the trailer without smacking the long pulpit on the winch post is a challenge. I think that a roller trailer, not a bunk trailer, is the way to solve this problem. With a roller trailer you don't have to put the boat as far into the water, so the stern doesn't float, pushing the pulpit down.
|L H G||
posted 03-01-2012 02:29 AM ET (US)
Dave - I think you've got it right from what I could tell with many experiences with Backlash. If the boat's keel is kept level with the ground and the trailer main frame, the forward crossmember rollers will keep the bow high as it rolls off the trailer. Burying the stern of the trailer is what causes the bow pulpit to hit when the stern starts to float in the water. An all bunk float on-off trailer gives no bow support as the trailer is submerged to get the boat to float off.
posted 03-01-2012 08:12 AM ET (US)
CONTINENTAL trailers appear to be only sold in Florida and then only from a few outlets. They don't have anything in their line suitable for a boat the size of a 23 Walkaround or Kevin's new Pursuit cuddy cabin. I don't think CONTINENTAL has a trailer suitable for anything bigger than a light 20-footer. They no longer show any big tandem axle trailers in their catalogue.
The notion that the keel of the boat must be maintained parallel to the trailer's frame is perhaps only an aesthetic consideration. For launching and loading ease, it would be better to orient the boat keel in the same attitude as it has in the water relative to the trailer's frame when on the ramp, and that would be with the bow lower than the stern. No matter what sort of trailer you have, aluminum, steel, bunk, or keel roller, the stern of the boat is lifted off the trailer by buoyant force as the trailer is backed into the water, and this always tends to push the bow down. A keel roller under the boat keel at the bow is useful to resist this force and keep the bow from plunging into the winch stand. The presence of a bow pulpit tends to aggravate this tendency.
posted 03-01-2012 08:58 AM ET (US)
Larry is correct - My previous post was a little poke at him. The trailer under my new boat is essentially the same model trailer as the Rohlfing's recently purchased, except that I didn't have my bunks custom fit to my boat, and I don't have the custom bow-stop arrangement. My new boat is similar in weight and size to the Rohlfing's boat. Larry's assertions that the trailer is of poor quality and cannot properly support the boat is simply absurd.
By the way, Jim, Continental offers a full line of steel and aluminum trailers: http://www.continentaltrailers.com/ . I don't have any problem with Continental trailers, but I do have a problem with the implication that any non-Continental trailer is a piece of junk.
posted 03-01-2012 11:03 AM ET (US)
I visited the link Kevin gives above and confirmed my estimate: CONTINENTAL steel keel roller trailers are only made for 20-foot boats up to 4,400-lbs total weight.
|L H G||
posted 03-01-2012 01:36 PM ET (US)
Kevin - I know you're used to doing it as a lawyer, but quit trying to steer the witness to make me look bad. And I hardly know or care what kind of trailer you have. Your comments about what I said regarding Jeff's Dad's trailer are simply incorrect. It was meant to be helpful but instead was taken with complete hostility. So be it. I could make some other comments here, but won't waste my time.
On the subejct of bow pulpits with anchors attached, I have two and neither hit the winch stand or even come close when launching and retrieving. On both, the keel of the boat when on the trailer is parallel with the ground and trailer frames. If you look at the last photo on Cetacea Page 78 you can see how high the bow pulpit is relative to the winch stand. I guess Dougherty knew what he was doing when he designed these hulls.
posted 03-01-2012 03:37 PM ET (US)
If the trailer set-up keeps the boat deck parallel to the trailer frame, and if the trailer frame is kept level, it makes it easy to work on the boat when on the trailer. I spend a lot of time working on my boat on the trailer, so that is a consideration beyond the aesthetic.
|L H G||
posted 03-01-2012 04:53 PM ET (US)
The other reason to keep the hull and floor st up at least level when on the trailer is to get rid of rainwater. This keeps the boat from filling up when traveling on rainy days, in thunderstorms or just sitting on the trailer uncovered overnbight, etc. I always trail with the plugs out in the floor sumps.
|L H G||
posted 03-01-2012 04:56 PM ET (US)
I just realized I had a good photo of how a big Whaler should be carried on a trailer. Note level keel allowing rainwater to drain, and how high the bow pulpit is over the winch stand.
posted 03-02-2012 09:00 AM ET (US)
The trailer under my 25' Whaler is a former commercial products division trailer and is set up with the all the keel rollers level. I do have trouble with the bow pulpit hitting the winch post when loading the boat, but looking at Larry's picture, the reason is obvious. My winch stand is very tall compared to Larry's. I guess some torching or cutting would fix the problem.
Here is my boat on the trailer. Picture Credit: Phil T.
posted 03-02-2012 09:04 AM ET (US)
What is the purpose of the post mounted mini bunks located right where the trailer frame starts to curve in toward the tongue? Are those for lateral stability or to help center the boat on the trailer?
posted 03-02-2012 10:58 AM ET (US)
Larry the bow pulpit hitting the winch post is not a design issue with the boat. It is an issue with the trailer, boat combination.
After owning a boat transport company for many years I am pretty confident that I have water loaded more boats then probably anyone on the forum.
There are many factors that go into bow pulpits hitting the winch stand:
If I wanted to spend more time I am sure I can find more reasons why a pulpit hits a winch post.
I do not think the designer of the boat has a lot to do with this. I hope the boat designer is making the best boat for when it is in the water not for when it is on the trailer.
posted 03-02-2012 11:10 AM ET (US)
This is a picture of a 23 walkaround on a trailer.
Notice the tall winch post, on some ramps it can be a challenge. Jeff's winch post design is a good plan I am hoping that I have room on the trailer to copy his design
posted 03-02-2012 11:16 AM ET (US)
Newt I have never seen a winch post so tall. No wonder it hits or you have interference. As you say easy to correct by cutting.
|L H G||
posted 03-02-2012 02:12 PM ET (US)
Newt - The forward supports are simply for lateral stability, and came with the trailer when I bought it new in 1989. Wedged against the boat hull, they really only stabilized the trailer frame from some deflection movement. At that particualr point, the boat hull was more dimensionally stable than the trailer frame! Recently, I removed, them, as I finally determined they were doing little good and not needed.
John - I would agree with you. The design of the trailer, and how the boat is configured on it, is what matters. About 95% of the Whalers I have seen in my lifetime are on terrible trailers, or not set up properly even if the trailer is a good one! I had such an experience with the "Sleezy Loader" that was furnished new under my 1986 Outrage 18. Within three years in the summer of 1989, the tongue joint at the trailer mainframe rusted through and separated at 60 MPH on I-94 in a center lane. Both the boat and myself are lucky to still be here!
I notice your trailer frame is very low to the ground. I have not seen an aluminu trailer slung like that. Is there a problem with it scraping the gound when backing down a steep ramp. That is a common problem I often see in FL with the aluminums.
posted 03-02-2012 04:15 PM ET (US)
Good eye Larry,
I had the axles under slung to lower the load.
She sits on the trailer at exactly 12' now.
The bottom of the v pad hits on a ramp now and then. But usually not a problem.
posted 03-08-2012 05:12 PM ET (US)
Larry, you have a great and tremendous knowledge of what has worked for you to haul your Classic hulls around and I do have a lot of respect for that knowledge. That said, just because it is not the way you would have done it does not make it outright incorrect. Like I stated before, each of us have our own baseline knowledge that helps us tackle a problem. Our knowledge going into this project is the same as yours, it was only based in classic hulls. The further we got into this problem it became clear that using what we knew from hauling Classic Hulls was not going to provide us with the best solution for our Post Classic Boston Whaler.
Also, to the level floor not draining....We have never had a problem with water puddling in the cockpit. While on the road and the high pressure windflow comes right off the top of the truck, and because of the lowered bow, it goes easily over the bow and does it's job pushing the water aft to the drains. Also, even in the flats of Michigan there are enough grade changes to change the angle thus moving the water aft and out. When the trailer is parked, the tongue jacket does the job to get things to drain.
Back on the topic of trailers for a 21 Walkaround-
I recently ran across a 21 Walkaround for sale and found it interesting that they had also created a which post set up like we ended up with. The bunks on this trailer look to be your standard straight running non-shaped pieces of wood which makes the keel run nearly parallel to the trailer frame; thus making the boat sit bow high leaving the deck sloping toward the stern. I am sure it drains well but, it does leave the center of gravity a bit higher than it really needs to be. I am sure it tows alright but, might tow better if it was lowered.
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