Go Back  Offshoreonly.com > General Discussion > General Boating Discussion
Cat v Vee ... a seriously, curiously ignorant question >

Cat v Vee ... a seriously, curiously ignorant question

Notices

Cat v Vee ... a seriously, curiously ignorant question

Old 01-26-2013, 11:15 AM
  #11  
Registered
 
Join Date: Jan 2012
Location: New Orleans, LA
Posts: 102
Likes: 0
Received 2 Likes on 2 Posts
Default

One of the biggest reasons that you do not see more large cats in the long distance races comes down to the physics of what makes a cat work.

Big cats when running fast are largely aerodynamically supported by their tunnels. For example a 40ft. Skater does not get into the ground effect regime until it is going ~ 80mph, below this most of the lift force is hydrodynamic.

When the cat is not in full ground effect the tunnel is much closer to the water which can cause tunnel slap which puts huge loads on the tunnel structure and causes very high acceleration loads on the occupants.

This means that for the boat to be able to operate in a way that does not wreak havoc on the boat and the occupants it must stay in ground effect even in large seas which for some of the large open ocean races is simply not possible.

This past year the avg. speed of the winner for the Cowes-Torquay race was 59 knots, about 10 knots slower than what a big cat would require to even get into ground effect.
MIskier is offline  
Old 01-26-2013, 11:54 AM
  #12  
Registered
Thread Starter
 
Join Date: Jan 2013
Location: SW1
Posts: 141
Likes: 0
Received 0 Likes on 0 Posts
Default

Ahhhh, eureka and cartoon bubble!

The answer to most questions is almost always 'physics,' and you distilled a bunch of amorphous thoughts quite well. Thanks.

Yeah, Vee Ganjavian's 38' Phantom made 60kts in some pretty rough & confused seas, and the other few finishers were significantly slower.

Cats CAN manage rough water, clearly, but there is a difference in a few miles of it, and a couple of hundred, too, I guess?
goatskin is offline  
Old 01-26-2013, 09:40 PM
  #13  
Registered
 
Join Date: Jul 2008
Location: San Carlos, Sonora, Mexico - Tucson, AZ
Posts: 70
Likes: 0
Received 7 Likes on 2 Posts
Default

US offshore racing hes evolved into a controlled/known environment that allows for higher speeds for a short duration.

Nothing to do with real offshore conditions over any span of time.
SinOjos is offline  
Old 01-27-2013, 07:54 PM
  #14  
Registered
 
Join Date: Jun 2004
Location: Freehold, NJ
Posts: 1,397
Received 15 Likes on 8 Posts
Default

I agree with the physics of how the cat works that is a given.

If any of you are old enough to have run alongside the old Popeyes 50' Cougar, Eric's Reality, Spirit of the Amazon or the 46' Skater Tuff e Nuff when they were new and in the prime you might say they could run in any rough condition. Those boats were all big, heavy with 4 engines and could out run any of the Apaches 41's, 47's in the rough.

Could they be good endurance boats, probably? Some people put the guy with the Gentry boat down a little when he suggested Detroit 8-92's in that boat. Well the Europeans all have always had factory support for their diesels, regardless of manufacturer the factory developed and supported them - we never had that here. We had people like me, the Merlin people with limited budgets trying to build hot rod diesels.

If you took a pair of 8-92's at 1.5 hp/cui they're 1,100 hp per side. What did Popeyes really have for Hp that they used 100% of the time maybe 1,200hp - 1,400hp and that put them over 100mph right? Look at haveing 1,100 hp that you could use all the time, the boat might run into the 90's and do that hour after hour after hour.

Take fuel consumption hopped up 8-92's at .38 lbs Hp/per hour is 418 pounds. Gas engines are at .53 lb hp/hr (?) so 1,200 hp is 636 lbs. You can start to see how you can carry a good amount more fuel with the diesel boat based on consumption alone. Your fuel weighs 1 lb/gal more but it still should win out.

So, your question of why not cats on the podium, maybe people just don't think they can because "that is not what we do in offshore"???
HabanaJoe is offline  
Old 01-27-2013, 07:59 PM
  #15  
Registered
iTrader: (5)
 
Join Date: Mar 2008
Location: Traverse City MI
Posts: 3,577
Received 260 Likes on 92 Posts
Default

Originally Posted by HabanaJoe
I agree with the physics of how the cat works that is a given.

If any of you are old enough to have run alongside the old Popeyes 50' Cougar, Eric's Reality, Spirit of the Amazon or the 46' Skater Tuff e Nuff when they were new and in the prime you might say they could run in any rough condition. Those boats were all big, heavy with 4 engines and could out run any of the Apaches 41's, 47's in the rough.

Could they be good endurance boats, probably? Some people put the guy with the Gentry boat down a little when he suggested Detroit 8-92's in that boat. Well the Europeans all have always had factory support for their diesels, regardless of manufacturer the factory developed and supported them - we never had that here. We had people like me, the Merlin people with limited budgets trying to build hot rod diesels.

If you took a pair of 8-92's at 1.5 hp/cui they're 1,100 hp per side. What did Popeyes really have for Hp that they used 100% of the time maybe 1,200hp - 1,400hp and that put them over 100mph right? Look at haveing 1,100 hp that you could use all the time, the boat might run into the 90's and do that hour after hour after hour.

Take fuel consumption hopped up 8-92's at .38 lbs Hp/per hour is 418 pounds. Gas engines are at .53 lb hp/hr (?) so 1,200 hp is 636 lbs. You can start to see how you can carry a good amount more fuel with the diesel boat based on consumption alone. Your fuel weighs 1 lb/gal more but it still should win out.

So, your question of why not cats on the podium, maybe people just don't think they can because "that is not what we do in offshore"???
Great Post!
offshorexcursion is online now  
Old 01-27-2013, 08:09 PM
  #16  
Registered
 
Join Date: Jan 2012
Location: New Orleans, LA
Posts: 102
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by HabanaJoe
I agree with the physics of how the cat works that is a given.

If any of you are old enough to have run alongside the old Popeyes 50' Cougar, Eric's Reality, Spirit of the Amazon or the 46' Skater Tuff e Nuff when they were new and in the prime you might say they could run in any rough condition. Those boats were all big, heavy with 4 engines and could out run any of the Apaches 41's, 47's in the rough.

Could they be good endurance boats, probably? Some people put the guy with the Gentry boat down a little when he suggested Detroit 8-92's in that boat. Well the Europeans all have always had factory support for their diesels, regardless of manufacturer the factory developed and supported them - we never had that here. We had people like me, the Merlin people with limited budgets trying to build hot rod diesels.

If you took a pair of 8-92's at 1.5 hp/cui they're 1,100 hp per side. What did Popeyes really have for Hp that they used 100% of the time maybe 1,200hp - 1,400hp and that put them over 100mph right? Look at haveing 1,100 hp that you could use all the time, the boat might run into the 90's and do that hour after hour after hour.

Take fuel consumption hopped up 8-92's at .38 lbs Hp/per hour is 418 pounds. Gas engines are at .53 lb hp/hr (?) so 1,200 hp is 636 lbs. You can start to see how you can carry a good amount more fuel with the diesel boat based on consumption alone. Your fuel weighs 1 lb/gal more but it still should win out.

So, your question of why not cats on the podium, maybe people just don't think they can because "that is not what we do in offshore"???
I agree that a big cat like a 40 or 46 Skater with a really steep tunnel angle can run in just about anything that a big v can. When talking about endurance racing though being able to run at 90mph to keep the boat up over an exceptional long distance is where the problem lies. Not being able to carry enough fuel is really not a terribly big problem to overcome if the boat were being set up for endurance racing from the start.

Funny that you mention Gentry, one of my professors has a bunch of old drawings from an endurance cat concept that Gentry had shortly before his crash.
MIskier is offline  
Old 01-27-2013, 09:11 PM
  #17  
Registered
 
Join Date: Jun 2004
Location: Freehold, NJ
Posts: 1,397
Received 15 Likes on 8 Posts
Default

You say "When talking about endurance racing though being able to run at 90mph to keep the boat up over an exceptional long distance is where the problem lies".

Can you explain that, what is the problem in your mind, people, boat, engine?

The big cats ran 150 plus miles years ago in Open/Super at those speeds, what difference would 200, 250 or 300 miles make?
HabanaJoe is offline  
Old 01-27-2013, 10:13 PM
  #18  
Registered
 
Join Date: Jan 2012
Location: New Orleans, LA
Posts: 102
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by HabanaJoe
You say "When talking about endurance racing though being able to run at 90mph to keep the boat up over an exceptional long distance is where the problem lies".

Can you explain that, what is the problem in your mind, people, boat, engine?

The big cats ran 150 plus miles years ago in Open/Super at those speeds, what difference would 200, 250 or 300 miles make?
All of the above,

Accelerations above 3g's cause problems for crew that are seated and long term problems for any crew exposed to it for an extended period.

Some of the current US built cats would need to have beefed up structural designs to cope with the conditions of a long distance offshore race.

Motors, as was said earlier the US lacks support from diesel manufacturers that would allow for a light very power dense marine diesel option to compete with the like of FPT.

Having a cat set up for endurance is very possible it would just require a departure from most of the current designs to have a boat that would be successful and safe in the types of conditions that are seen during races like the Around Britain or Cowes-Torquay-Cowes.
MIskier is offline  
Old 01-28-2013, 12:33 AM
  #19  
Registered
Thread Starter
 
Join Date: Jan 2013
Location: SW1
Posts: 141
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by MIskier
... Not being able to carry enough fuel is really not a terribly big problem to overcome if the boat were being set up for endurance racing from the start. ....
European seas are rougher, regardless a/o endurance boats are heavier and more overbuilt. There are a couple of successful lighter exceptions, OL is one that comes to mind, and is very successful in the GPS-Evolution class (read: slalom), but OL are 'overbuilt' in their own way.

I think that only KeraKoll a liposuctioned Buzzi 48' with FPT-650hps and Metamarine, a 46' who went the other way, SeaTek-950hp have had any notable success in slalom with diesel, but both have won several A-to-B races - their actual design condition.

I don't think very many cat builders add much mass on purpose. Their market is poker runs, not endurance, physics aside.

Plus, just showing up on race day and finishing is not enough: you have to train in seas, too.

Originally Posted by SinOjos
US offshore racing hes evolved into a controlled/known environment that allows for higher speeds for a short duration.

Nothing to do with real offshore conditions over any span of time.
Maybe IF there were some of the old-style races? The KW long course? 145mi or the 'Storm Course' of 75mi?

There has to be racers AND boats AND courses. If there is neither purse nor glory, there won't be a Miami-Bimini-Miami.

Originally Posted by HabanaJoe
... the old Popeyes 50' Cougar, Eric's Reality, Spirit of the Amazon or the 46' Skater Tuff e Nuff ... they could run in any rough condition. Those boats were all big, heavy with 4 engines and could out run any of the Apaches 41's, 47's in the rough.

Could they be good endurance boats, probably? ...
...
So, your question of why not cats on the podium, maybe people just don't think they can because "that is not what we do in offshore"???
So ... there is a chicken & aig problem?

Admittedly, UIM is hostile to diesels, and to cats, invariably, when racing outside of Dubai rules.

I see no reason the Gentry could't run neither, and there are better, lighter diesels to get 2-3-4000hp than cast-iron Detroits.

Last edited by goatskin; 01-28-2013 at 01:16 AM.
goatskin is offline  
Old 01-28-2013, 07:31 AM
  #20  
T2x
Allergic to Nonsense
Platinum Member
 
T2x's Avatar
 
Join Date: Aug 2001
Location: Granite Quarry, NC
Posts: 5,011
Likes: 0
Received 17 Likes on 17 Posts
Default

Jean Pierre Fruitier won the Cowes Torquay race in a cat ("Rocky") back in the late 80's or early 90's. Cat s have also run and won rough (and calm) water races in the UIM all over the world.

T2x
T2x is offline  

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.