PT Boat modeling question.

[akbmzawy]

I have done some searches for this question and have come up blank.

Wiki has info about the boats, but just a basic history and performance with diffrent engines.

I am curious about the modeling of the boats when engines are cut or reduced to idle quickly while in gear.

The weight of larger ships and boats can allow the vessels to take a lot of time and distance slow down or to stop.

In AH the PT boats take a long time to slow down and to stop. I don't think that this is modeled correctly as boats this size could eject people into bulkheads or overboard. Water is a big drag with 3 propellers or screws in idle or stop.

Is the PT boat modeled correctly to the weight and drag to not slow down quickly?

[Buzzard7]

Well Pt boats aren't exactly small. Elco made one that was 80 feet long. All of them had 3 v12 Packard motors. I don't see any info on weight yet. 70 -80 hull might take a bit to get her stopped.

[Rino]

     You can stop fairly quickly by putting the engines in reverse then throttling up again.

[akbmzawy]

Yes that can be done. I am questioning the modeling.

[Scotch]

You're asking if leaving the boat in gear with throttle reduced should slow it down very quick? Like a lot more than putting it in neutral?

[akbmzawy]

Yes, exactly. It's more parasite drag.

[Scotch]

Okay.
From my experience driving a 52'x15'x8.5'  41ton wood crab boat (1 screw)...
Firstly, if I put it into Neutral, it will disengage from the shaft and stop my screw from spinning. If I put it in gear, even at idle, it engages and turns the prop. Hell, my boat idled at about 4.5knts.

Now will stopping the screw slow the boat faster than leaving it turning? The difference is there, yes. But not worth worrying over. It's not going to instantly stop you either way. Would 3 screws add more drag? Yes, but props themselves aren't that large, and are designed to minimize drag, so it's negligible.
Of course my avg speed was about 7.5knots, not 30knts, or whatever those PT's might go. You will see different effects at higher speeds.

I would be curious to know the dimensions of the PT boat we have, as draft(how deep it sits in the water) will have the largest effect.

[akbmzawy]

I have had 2 boats.

One was a 19 footer with a 150 merc outboard. The other a 21 foot cuddy with a 304 6 cylinder. Both aluminum v hulls. Drastically a lot lighter then an 80 foot PT boat. My draft was about 15 inches for my first one and 19 inches for the second one.

Both of my boats would do about 40 MPH at cruise. Reducing the throttle to idle was like hitting the brakes. I used my boat in the Missouri River so debris in the water was common. Sometimes the violent manuevers were needed to avoid logs. Anyone standing up would be thrown forward.

Weight is the determining factor here so the original question still stands. Are the PT boats modeled correctly for slow down rate?

Oil tankers on the oceans do take miles to stop.

[bj229r]

A better question about modeling is WHY do PT's ALWAYS explode, and never sink over a span of even...10 seconds? That would normally afford the chance to be awarded the kill on the tard you shot out of the sky

[AKP]

A better question about modeling is WHY do PT's ALWAYS explode, and never sink over a span of even...10 seconds? That would normally afford the chance to be awarded the kill on the tard you shot out of the sky

A better question... why is it you cant "land" a PT boat?  I have never seen anything but a ditch in one. Is it possible to successfully end a sortie in a PT?  Every time I up one, I am either killed (with no chance to swim with the sharks), or I ditch when I EF.

[akbmzawy]

It seems no one can answer my true question so far. To answer AKP, yes you can land successfully in a PT only if you are inside the fleet close to the CV.

[Simaril]

You have to keep in mind what PT boats were designed for. They were the 30s and 40s equivalents of those massive cigarette boats around now.

They were designed for high speed attack runs against heavily armed and armored vessels. Their only hope for survival was speed. And to get speed in the water, there has to be low drag built into the design...(No way you're going to get a landing craft infantry going that fast, no matter how big an engine you put in it!)

So low drag is automatic. They're sleek and slick in contact with the water. They're speed boats with torpedoes.

Now, you're right that the props will give some drag. But in the overall picture, their contribution is going to be small compared to the effect of that long, shallow, slick hull. They will coast a long long way.

I'm not an engineer, so I can't go farther than that. But the overall picture I get piloting a PT feels right to me.

[Simaril]

A better question about modeling is WHY do PT's ALWAYS explode, and never sink over a span of even...10 seconds? That would normally afford the chance to be awarded the kill on the tard you shot out of the sky

Wooden ships, loaded with gasoline and explosives.

Explode rather than sink? Reasonable shorthand for a game like this that focuses on the air side rather than the naval side.

[caldera]

A better question about modeling is WHY do PT's ALWAYS explode, and never sink over a span of even...10 seconds? That would normally afford the chance to be awarded the kill on the tard you shot out of the sky

+1 on that idea. 

[Tyrannis]

A better question... why is it you cant "land" a PT boat?  I have never seen anything but a ditch in one. Is it possible to successfully end a sortie in a PT?  Every time I up one, I am either killed (with no chance to swim with the sharks), or I ditch when I EF.

ive landed a pt boat once with 2 kills.

im not 100% sure of this, but i think you need to run it up on a the beach close to a friendly airfield.

when i got my 2 kills i was trying to provide some cover fire for the lvts but when doing so, got stuck in the sand or w.e, after the base got captured, i ended sortie. and it said "you have landed succesfully"