Speed Rails - fact or fiction?
 

So, what do you all think? Anybody tried them, or is this snake oil?

http://www.thunderoffshore.com/roca.html

Interesting results...5-18% speed gains.
I rack my boat and they have problems without those things.

Canada Jeff, you bring up a very good point, seems most bunks(trailer or lift) lift right where those are mounted.

Also, so who will be the first guinea pig to try these things. Probably...........no one?

By looking at the picture I would agree that a tralier, rack or lift might do damage. I would also tend to think that there are boats out there that would not benefit form those things. My velocity rides on a pad which means I am already on top of the water. Warlocks and Fountains do the same thing so I would think that these are meant for older more deep v hulls.

An example of that would be an older Scarab vintage 1986 or so. These boats have no pad nor do they have a stepped hull, at that time, so they ride deep in the water. By using these speed rails they force water down pushing the boat up out of the water creating less drag and faster speeds. Remeber this only makes sense in theory. I think they would work well for some people and not well for others and the application needs to be looked at closely first.

Although Mark your Sonic is a true deep v hull maybe we should put some on and try it. After that you might not want to sell it:D

Oh yeah sorry for calling so late last night.

I have speed rails integrated into my batboat and believe they are part of the reason my boat runs so extremely well in calm and rough water. I posted positive comments about them on OSO when I noticed the ad and requested info from thuderoffshore. They never even returned my email. Seems like a waste of ad dollars to not even follow up on prospects.

I contacted Ocke mannerfelt who invented them www.ocke.se and he got back to me right away. Anybody interested in boating should visit ocke's site as he has designed everything from huge ships to ribs to batboats.

I had thought about the trailering problem, but they would not hit my bunks. The strap issue is something I had not thought of.

Would you have to screw those things on to your nice water tight hull? Not sure I like that! :eek:

I asked them the same thing. I'll post the response when I get it.

I was looking at these as well. My hull has a rounded keel (92 Four Winns Liberator )and large strakes. I can see where the rounded keel would push water out to the sides more. I would want to mount them with 3M 5200. From what I have been told, you would not need screws with 5200 but would damage the hull if one got ripped off.

Speed Rails were or still are a
product that Volvo Hi-Performance
came out with in the Mid 90s I
beleive, I was involved in the
Early Bat Boat and Volvo during
that time.
The Boat was the Rain-X A-50 and
te speed rails were added to the
bottom but I did a full inline
Canopie at the same time so the
Boat rode a lot different.
At This shop Speed Rails were
added to a 29ft Scarab but were
Scuffed off in the Rough SoCal
Water and never put back on.
The Rain-X boat went to Florida
for a season and returned to SoCal in 1996 for a APBA race in
Ventura and I noticed the Speed
Rails had been removed.
Hope this answers some of the
Questions.
Mike J.

I tried a set several years ago. you could definitley feel the boat lift a lot more out of the water and the ride was more harsh, but I didn't see any magical increase in speed. I had them screwed on along with 5200. One ripped off and left some nice holes in the bottom. They also dug into the trailer bunks and tore the carpeting when hitting the trailer at a less than perfect angle. I took the remaining ones off and gave up on them. I think the concept is good but too many problems mounting them as an addon.

I would think as alluded to above, that the increased lift would cause increased chine walk much like smaller but fast lake boats with great lift for speed. Also the affixing to the hull with whatever method presents itself as a hazard whether in the rough or simply pushing up on the beach for cold totti. My vote is snake oil...

.
 

Read TOFFENs post 0f 11/30/02

You have to give Awkward Monohull credit...He has come up with more ways to try and make a vee hull lift off the water and fly than anyone in history...... sadly he has missed the point that this has already been done..and better by an earlier design......It's called a catamaran.

Years ago old lonesome George Linder and I were racing vee bottom Eltros...This was right after the civil war or the Beatles...I forget which.......

Anyway.... We encountered the first tunnel hulls, which promptly made mincemeat out of our previously dominent race boats. So we spent this long Saturday afternoon modifying vee hull drawings...... we drew wings mounted to the decks...sticking out the sides.....over the motors....on the drivers helmets (Hey Ocke, there's one you missed!!!).....etc, etc.

Then I drove my first tunnel hull.........and all the "Flying Vee" nonsense stopped.

But I do admire ol' Shaky Marigold's tenacity ......he does not waiver in his belief in the driveable lawn dart. How that has bred a legion of zealous followers is truly a wonderful mystery.

T2x

Well put T2x......MikeJ I know you were involved with this west coast project and I believe we probably know or knew in one case all of the people involved

There was a report done on these years ago by one of the mags, powerboat I think. Ill try and find it. Results were not good.

it all depends on the boat. speed rails do work. but yes loading and off loading would kill them. at the races we use a crane so there is no damage. usally speed rails are added because there is somthing lacking. if the hull is done right the first time don't need them.

Treadwell

I have been truly enjoying “Speed Rails” and the “Stepped Bottom” threads. I spoke to T2x earlier tonight, and he asked me if I visited the “Speed Rail” thread? My reply was, no not yet. T2x then said I should read about Okie Dokie Mayonnaise’s speed rail bottom add on. I think they are made by the same people that make the “Bass –O-matic” Wasn’t that on SNL? Ronco makes the speed rails, or Okie fonokie. Oh well T2x is drawing a helmet wing. I hear he is holding auditions for a test pilot.
Philip

I am off to the "Step Bottom" Thread. I don't want to miss anything. What was that about Shock Wave, and some fuzzy little things?

Thanks for the comments. I guess I'll leave my old Cigarette hull alone. It was meant to do something, and it does it well.

I promised to post responses I got from the people that sell the rails. Gene has been very responsive to my emails.

========================================

Hi Steve,

No problem on the questions, I spend the better part of each day answering questions anyway.

Yes, the rails attach with 5200 adhesive. They also have 6 screws on each rail #10x1/2" to hold them on while the glue dries. The screws can stay or be taken out after the cure time. I recommend leaving them on. Yes the rails can be removed but will require a little gel work to fill the 1/8" holes. You should not see any decrease in speed whatsoever. The only negative we have seen yet is a little noise from where the spray is :bouncing" back up on to the bottom. I'm not even sure you would hear it in a Cig because they are built so well.

We just completed a 34 Baja. The boat turned A LOT better after the rails were put on. We had a 2mph increase at 3500-4000-4500-5000-rpms at each speed. We got a 3mph increase at WOT. The boat behaved well with just a little bounce in a hard turn at WOT. All said, I call this one a success.

I think this data could be even better if we "tweaked" the placement a bit. This installation was done exactly to the mfgrs recommendation, the customer was thrilled.

Let me know if I can be of further assistance.

Thanks,
Gene

Sean: Yes sir im sure we know all
of the people involved With the
Volvo HI-Performance Group.
That part of my life is one of
those 3am "What ifs" that we all
have, What if I would have stayed
with the Navy Special Weapons
Group and not let myself get talked into that deal.
That is Why im staying off the
Step Bottom Thread.
Mike J.

Guys, this is not hard to figure out. As was stated earlier, the speed will increase when the drag is reduced. Properly installed speed rails direct the water down which will lift the hull, decreasing wetted surface. Every little bit helps.

Now if you really want to lift a hull, try forcing a 42 inch high column of air through an 18 inch opening under the back of Skater or MTI cat. This really helps.

Now the steps.

Next the X goes up and the drives go back (boxes) and the notch, so you can still get on plane.

Now you are broke but fast.
:D

BTW, I tried them on porposing 38 Topgun. Gained 1 or 2 mph and reduced the hopping significantly.

Wonder if these would help reduce the 'hop' on my 26 Ocean Express, it has a slight rocker to the rear of the sponsons and small 12" pads? My Cat seems to pack air then falls off it, I'm thinking this might trick the hull into a more bow down(i.e.forward C/G as if ballast were added) I have two 250 Yamaha's that are heavier than Merc's. and at WOT it really hops huge on calm water. Any suggestions? Thx,Bill:confused:

I think a tunnel tab, or flap, would work better and it should be abjustable. JB

John B, I agree......or a wedge in the tunnel......

A tunnel, by the way, is the best "speed rail" you can buy.

T2x

T2X, speaking of packing and unpacking air, I have a 30' cobra single engine which has a tendency to do this or poipose. It sprays out the sides like the steps are venting the tunnel. Did you mention earlier about sealing the tunnel side of the step to keep the air in the tunnel? I guess a thin piece of SS on the inside. What do you think?

Try 3/16ths.......aluminum on slide mounts to adjust...Start at 1/4" below bottom at transom, ending flush with the steps. A single engine cat is the toughest bird to tame.

T2x

Boating Mag. August 1994. Article called "Cutting Edge". If anybody wants to see it, email me and Ill scan it and sent them a copy.

Speedrails test
 

Hi!

I have tried them....

I have a Phantom 25 Offshore hull with a Promax 300 outboard. Its bow heavy and need lots of positive trim. It runs fairly quick - 76-78 mph at 6100-6200 rpms spinning a blueprinted Tempest 26. Gearratio 1:1.75. The boat weights approx. 2.500 pounds incl driver and 10 gallons of fuel.

I mounted four speedrails according to the book. Two in front and two 75% towards the stern. This should create bowlift. We used Sikaflex and the speedrails turned to be almost impossible to take off.

It proved to be a great miss. The boat ran higher, but flatter. The top speed decreased approx. 3 mph. Cruise speed increased 1 mph. The boat runs 53 mph at 4.000 rpms. Now it ran 54 mph at 4.000 rpms. It did turn fairly well, but it turned much more precise without.

I pulled off the two speedrails towards the stern keeping the two in front. Top speed increased somewhat, but still 2 mph lower than without. The boat started to porpoise as well at 55 mph - 60 mph.

The speedrails may work on heavier hulls at lower speeds. For me they were a pain in the ****.

I rather advise the following: a) get rid of extra weight; b) rebalance the boat; c) blueprint the bottom; d) play with propheight / x dimension; e) play with props; or buy a Skater...

Good luck!

Cheers, Toffen

Way to go Toffen!!!!!!!!


And he comes from Axle Manygimmicks' back yard.

T2x

I am still Baffled by Swedens answer to Edison Airfoil shaped Tie bar Invention. T2x I would venture to guess it would be used in conjunction with the Helmet wing.:confused:

They don't have back yards in Sweden. They pile up all there belongings that they accumulated their whole life and are buried with them. Whoever has the largest pile wins. They were way ahead of the "he who dies with the most toys wins crowd." This was way back in Viking times when the guys called berserks would eat magic mushrooms and sneak up on you in canoes (with steps of course) sometimes carrying the boats across many miles of land. Speed rails were just a convenient way to store their swords when the boat was upside down. They also invented dissecting people to study them. I think it has something to do with 24 hours a day of no sun in the winter. Nonetheless I will continue to drink Ocke's coolaid until I get my new 28 Skater. I was contemplating a new Saber, but somebody said they were a cult too. Geelhood or however it is spelled sounds Sveedish too. Come to think of it, what about Hdlein?

I heard a Sweed married a Palestinian and they named their first son Yasser You Betcha.

No offense meant to Sweeds, I was fascinated with the burial mounds and Berserks on my several visits there and all that was taking place while Americans at the time were still trying to figure out rubbing sticks together. Sweden has one of the longest boating histories in the world if not THE longest. Viking helmets were the first with wings, even before T2x.

The Swedish Vikings...haha..had a city called Hagsta by the Baltic west coast a canoetrip from the east coast where they tried to settle..with as much success as in Vineland...and moved to Birka.
Regarding war heroes Swedes are best at "recruiting" others. Therefore the Finnish bestseller "Swedish WW2 heroes" is a short pamflet with forewords only..
But come to think of it Luhrs sounds Galllic and those pagans did have helmets with wings, just like Fabio Buzzis (rip) ancestors before christ....

So who has the bragging right for winged thingmajings?

personally have found the speed rails to help best turning sharp with vented bottom...Speedgains dunno...

In addition to SpeedRail, Ocke Mannerfelt designed some very competitive cats.

But maybe Victory Team couldn’t find Rich Luhr’s phone number, or didn’t know how to use the PM function on OSO.

I have a set on '73 Chris Craft XK-22. Long story, but I'm the third generation to own the boat. When I helped my dad restore it in the early 90's, we installed a set of Speed Rails and the boat picked up 500 rpm. Not sure what that equated to speed wise, but the boat handled better as well.

I repowering it as we speak and am going from a Volvo DP to a Bravo 1 with dual ram hydraulic steering; curious to see how it handles compared to how it used to handle.

Fact!

Ocke Mannerfelt was an Scandinavian designer who was commonly known because of his world champion boat with wings. The “bat boat”.

His biomorphic and fusiform designs are very recognaiseables.

But is best developments where at wet area of the hull.

His hulls always has few strakes, all of them very sharp and with a concave design which were specially made to use the energy of the lateral water displacement.

Also he had a very smooth design of the steps with the best study of the different angles in them.

Once, he realise most of the European sport boat they had very narrow and not prominent strakes causing the boats to a poor lift and instability at high speeds.

The Roca Speed Rails were just a simply screwed-able aluminum slats fixed to the strakes. They were concave as in Ocke boats.

In USA they weren’t very successful. I guess because US boats use to be builded with wide and prominent strakes. Non extra is needed.

Im still looking for a set to be mounted to the slim strakes of my boat.

If some fellow has still a set left, please keep in touch!

Javier.

Can someone post a picture of these? The link in the first post doesn’t work.

try this one:
https://www.mdteam.se/projects.html?speed_rail