That’s a Cornell Maritime Press publication… probably out of print, because i don’t readily recog the title. but if anyone interested, just know that CMP has good books on the subject of naval arch and hydrodynamic still… you can buy online direct too.
-j
IMO,
the top one looks like a displacement hull with a real low pressure system right about where a single fin would be, and the bottom is a plane, more like the back half of a Casper, which has its fins outboard where pressure/lift are happening, and also has concave(s) inboard of the fins to direct more lift inboard. The tail of Liddles and the other hullish midlengths seem to be all about decay of lift (line) to allow it to come around the drag off the bow, which is the Vee shape dark area in the graphic. The Casper’s concaves direct the lift inward off the rail/bottom, so the dark portion would be where the low pressure white area on the hull is. This is in an on-rail trim or turn.
There’s entry hull on the Casper, and a relatively decaying outline in the tail, but they look way different to me in terms of all the directed hull and fin lift that’s happening back there, which is evident in the shot I posted on the other thread of RK filleting an overhead pitching lip…
You are right. I think that this is why Simmons thought to put the concave in the tail. He was trying to get rid of the suction that happens at the tail end by adding concave there.
I’d agree that Simmons put in the concave to deal specifically with the low pressure system they describe with that graphic. I don’t think it’s suction in the hull graphic, per se, but loss of lift, closer to zero pressure than negative pressure.(?) Liddles apparently tend to spin out–if they had more drag (negative pressure–suction) or more rail fin lift (positive pressure, pushing the rail into the water) back there, they wouldn’t do that. They’d be tighter, but they’d lose speed.
This is exciting, knowing Simmons read this book:
And here’s how you catch more waves:
One designs characteristic I am wondering about has to do with the profile. The Naval Architecture of Planing Hulls photos reveal a profile that tapers back from a wide point way forward toward the nose. Simmons boards are more parallel with the aft sections containing the widepoint closer to the tail section. I also notice on his boards, the last 3rd, starts to cut in just above the middle of the last 3rd. Is this his 15-20 degrees of attack angle?
I’d agree that Simmons put in the concave to deal specifically with the low pressure system they describe with that graphic. I don’t think it’s suction in the hull graphic, per se, but loss of lift, closer to zero pressure than negative pressure.(?) Liddles apparently tend to spin out–if they had more drag (negative pressure–suction) or more rail fin lift (positive pressure, pushing the rail into the water) back there, they wouldn’t do that. They’d be tighter, but they’d lose speed.
I would say you are right, again. Although, suction is negative lift, and relative to the fore portion the aft portion is creating suction. According to the book, lift is at it’s maximum at the leading edge, where the water and the hull first meet, and the lift ramps down towards the aft portion.
Here’s a 7’2 I made last spring. I got the template off my buddy’s 6’0 swift movement board. I pulled in the tail a little bit and added a thin tail block to control the possible twisting of the foam since the tail is so wide. It’s PU/PE instead of the eps combo. There’s no rocker whatsoever. The rails and foil are quite a bit thinner than the swift movement board, I kinda just did my own thing. Didn’t really know what do expect for the most part, but this board works unreal pretty much anywhere I’ve taken it. Ankle high and gutless to double-overhead point breaks, this thing has handled everything I’ve put it through. Did a little camo ink ejecting squid resin art too.
Here’s a smaller and thinner 5’3’’ variation. Eps #2 with 4x4 x 4 e cloth. This board is really really picky about the wave it wants, which happens to be bowly point breaks, or something that’s not mushy. drives unbelieveably hard off the bottom, kneeboard take offs too.
Hey obs, I dunno–I was thinking that area was closer to zero pressure. There has to be a continuum by definition of the terms positive and negative pressure, so there has to be a zero pressure or near-zero pressure in the continuum.
The area behind a hull curve into a really flat rocker would have more like zero pressure… if the curve continued and there were a back side to the curve, it would have separation–separation is drag/suction/negative pressure, so a Liddle and a Simmons both have flattened rocker behind the hull forward, for the flow to continue along–they share this much–the hull forward to flow over and through bumps, belly to aid banking a wide forward board and the flattened rocker behind to give the flow something to flow along without separation.
But it seems to me that Simmons put the belly in the forward area to lift the nose until you could put it on rail, and put the concave in the tail to direct lift inboard, which is, I think, just about the opposite of the Liddle release tail. A board like that, with concaved tail, with fins at the rails, is able to be ridden from forward trim or on the tail with the right fin configuration and esp the trademark little break in the outline to straighten off back to the tailblock.
The S deck seems, like I said elsewhere, to be a simple mass-reduction element, which has been held over from balsa and heavy foam days for a combination of semi-aesthetic reasons.
Anyway, here’s a link to some interesting info: http://www.legendarysurfers.com/surf/legends/ls15.shtml
that was such a fun read! I can’t imagine what it must have been like to be on the forefront of design back then… and pioneering those spots… especially the Sloughs…gnarly!
Dave
Cool boards, Tonybanger. Lets see some more. Mike
The mini simmons always looked like very functional and fun boards. Have been reading all available info on simmons and his creations, hope someone will wright a book about him someday.
After finishing my glider, a 6’6-6’8 simmonsesque board will be up next. Trying to stay true to his concepts, especially the wide tailshape(I think gross used a greenogh spoon type tailshape on some of his simmons boards), but why not tweak/change the fins?
Keeping the early entry"catches waves in the middle of the ocean" and blissfull trim with the wide tail, but instead of narrowing the tail with wings and adding a trailer like the “simster”
or giving it a swallowtail like the whitepony
Why not give the board a little more hold with maybe twinzer or quad fins?
I agree with you about tweaking the board for the better, but it seems that the whole point of the Simmons boards is to stay true to his design.
What I question is whether his designs are flawed. Joe Quigg worked with Simmons when he was making these boards and Joe’s designs ended up in a totally different place. I don’t think anyone will question the validity of Quigg’s boards, they went in the right direction.
I recently had a chance to see a mini simmons being surfed in Hawaii in overhead south shore and I talked to the owner. It seems that the board does not ride as well as a good fish, but that’s not why they are popular. I think the retro trip is what this is about. Similar to what riding an Alaia is all about. Performance surfing requires a very specific combination to make the right board, but fun boards don’t. The key word is fun.
Personally I think the Mini-simmons is the perfect way to incorporate Bob Simmons designs into a boards that will work well. You’ll probably stand in one spot all the time. Going longer like over 7 or 8 feet doesn’t help. The nose is not designed for riding up far, and the tail is too wide for a lot of hard turning. I’m still not sure that a tail that wide will perform really well if you want to be on the rail turning hard. I have several short wide-tailed boards and when the waves get to be solid overhead they have too much area in the tail. They get really squirrely.
Good surfers can ride anything, but that doesn’t mean the boards they are riding are any good.
I think your idea of making a quad or twinzer will improve the performance, but destroy what the whole thing is about. I was also planning to make one, but I just don’t see a good reason to do it. I think using his bottom and rail designs on a modern outline make more sense. That leads towards a bonzer, thruster or modern fish.
I changed the basic design of the McCoy nugget and Downing slippah to have a flat bottom up front and I have been very happy with the way I can step up on the nose and plane through flat spots. With a Simmons design you have the rounded off bottom up front and you can’t do that. I like the Nuggets and Slipahs, but if the tail isn’t thick enough for the riders weight, it doesn’t ride as well. These boards are designed to stand on the tail and take advantage of all that area. Keone wanted me to ride a shorter one, but I didn’t think my strength to weight would work out. He was right about the length, but I need more thickness to cut back on the length. So the short simmons boards make sense, but I was told that the thickness made it a problem to push through waves. What I do is stand on the board to get it to sink then just before the wave gets close get back on your stomach and push through.
rooster,
I have 2 more simmons type weird contraptions I made during last spring, but I gotta get on some photos. asymmetrical fins and such. I sold them to my buddies, I’ll ask for them back and get a picture sooner or later. I do remember running into you on the eastside a while ago. I was the one with that stringerless asymmetrical fin’d rainbow hull fish.
-tony
Sharkcountry, Don’t get me wrong, I’m not after more performance, this board would be used just for fun. Setting up, catching and making small fast zippers that would otherwise surfed with my 11’6 glider. Can’t bring my 11’6 with me to Scotland or Portugal, so a minisimmons would be a great substitute.
Changing of the finsetup cameup when I read how slidey and slippery theese boards can be especially backside. Just don’t want to end up with a board that has to be nursed or requirers “finesse” when bottom turning or cutting back.
Maybe I’ve got the wrong idea, just thought a twinzer or quad set up would make these boards moe userfreindly while maintaining most of simmons ideas.
Recently, Terry Martin and Jeff Quam collaborated on a set of Simmons inspired boards. Of course they took some liberties as the goal wasn’t to make a true replica. In their discussions they made a few changes to the board that they felt were in keeping with Simmons spirit of innovation. One example is the four fin set-up which Terry felt Simmons might have incorporated had he been around for that particular performance innovation.
Three sizes were made only two of which are shown here. The blanks used had no wood stringer and instead only had the high density colored foam stringer. I can add the dims later after I get them from Terry/Jeff. I’ll also see if we can get a few more pics that show more detail as to shape.
Here are a few shots.
Just saw the post of Terry Martin’s latest Simmons boards. It’s what you were talking about. I think you have the right idea. From what I’ve seen and read about you can go very short with this design. They seem to be a lot of fun to ride, and they are fast. I think it would be a great travel board with a set of box fins.
Why not give the board a little more hold with maybe twinzer or quad fins?
I did, and this is the most fun I have had in a long time…
i obviously pulled in the nose a little as well, and it has a double concave/spiral vee thing happening, but it runs like a raped ape and goes on a rail with no speed loss whatsoever…stoked!
(more pics in the resources)
Ha ha, great pin lines.
Do these have some specific rocker numbers or is that changeable too?
Can you tell me what lengths the boards were?