Being a landlubber I didn't know any of this...thank you for expanding my knowledge of ships.

quote:

Originally posted by LS1 GTO:

As a side note, pretty sure the carrier can outrun them all to possibly include the subs' torpedoes.

As a side note to your side note, a friend told me about watching on sonar a Skipjack class submarine run away from a Mk. 46 torpedo during an exercise.

Here's a link to a high res version
You can see there is a visible wake, it's just dispersed more due to the size of the ship.

Thanks for the new background photo!

quote:

Originally posted by lastmanstanding:
See those doors in the aft? It could be a caterpillar drive.

Lol well played.

All the information about hull speed and waterline length is true, but what you are seeing in the photo as "wake" for most of the vessels is the bubble trail left by cavitation of their variable pitch propellers.
The Nimitz and Ford class carriers have big fixed blade props powered by steam.
The cruisers/frigates/destroyers in the photo are most likely all gas turbine powered with controllable pitch propellers. When participating in close quarters/formation maneuvers, they have their shaft speeds spun up high and their propellers pitched fairly flat, it provides for very quick responsiveness, also makes a lot of bubbles via cavitation.

Good thing the B-52's in the photo are "H" models with the TF-33 engines. "G" model Buff's with J-57 engines would obscure the ships in a cloud of black smoke, thereby ruining the picture.

I can't believe the submarines would travel that close together while submerged.

Hull design and hull length. A ship displaces the water up until a certain speed (called hull speed), the longer the ship the faster it's displacement speed, which takes very little HP (in comparison to faster than hull speed) and also leaves little wake. Exceeding displacement speed takes a lot more HP and makes a wake in semi-displacement and planning hulls.

I found an article stating that the USS Enterprise made over 40 knots during sea trials. That translates to about 46 mph. That's faster than my bass boat, and THAT just blows my mind!

Thanks for the fascinating discussion. I had no idea about much of this!

quote:

Originally posted by lastmanstanding:
See those doors in the aft? It could be a caterpillar drive.

Give me a ping, Vashilly. One ping only, please.

you can learn a hull of a lot reading this...

Uh huh.

quote:

Originally posted by Todd Huffman:
I found an article stating that the USS Enterprise made over 40 knots during sea trials. That translates to about 46 mph. That's faster than my bass boat, and THAT just blows my mind!

We had an Iranian Small boat screw with us last deployment in '06 or 07 - the plane guard destroyer was trying to stay between it and the CVN, but the little bugger got by. An HH-60 was still in between and ready to light it up if need, but then the CVN Captain turned HARD away and dropped the ship into warp drive speed. The ensuing wake nearly swamped the Iranian boat and we left them in the dust.

They didn't try that again.

Depth of propeller might also have some effect on wake. Greater depth = less surface disruption. Some in that pic (submarines?) might even have their propellers breaking the surface. The blades “stir” the air into the water.

As noted by Captain Mike, cavitation makes bubbles, bubbles make white wakes.

This thread is fascinating. I would have never thought the carriers would be so quick.

quote:

Originally posted by Chris42:
Depth of propeller might also have some effect on wake. Greater depth = less surface disruption. Some in that pic (submarines?) might even have their propellers breaking the surface. The blades “stir” the air into the water.

As noted by Captain Mike, cavitation makes bubbles, bubbles make white wakes.

Totally unrelated to the photo, but super high-speed propeller-driven boats often use propellers that are part in and part out of the water.

Partially, that's because a surface-piercing propeller can reduce drag, but a lot of it is because they reduce cavitation, and at super high speeds, propellers experience intense enough cavitation that it basically "eats" the propeller over time.

This is the main surface-piercing propeller system I've seen, the Arneson Surface Drive.

http://www.arneson-industries....e=products&id=drives

Maladat - I agree.

quote:

Originally posted by maladat:

quote:

Originally posted by Chris42:
Depth of propeller might also have some effect on wake. Greater depth = less surface disruption. Some in that pic (submarines?) might even have their propellers breaking the surface. The blades “stir” the air into the water.

As noted by Captain Mike, cavitation makes bubbles, bubbles make white wakes.

Totally unrelated to the photo, but super high-speed propeller-driven boats often use propellers that are part in and part out of the water.

Partially, that's because a surface-piercing propeller can reduce drag, but a lot of it is because they reduce cavitation, and at super high speeds, propellers experience intense enough cavitation that it basically "eats" the propeller over time.

This is the main surface-piercing propeller system I've seen, the Arneson Surface Drive.

http://www.arneson-industries....e=products&id=drives

I run some Arneson surface drive yachts. Ships don't have them as they do not maneuver well at idle speeds and docking situations at all. Nor do they do well at getting heaving boats on plane (they simply won't).

You normally see them in a small percentage of 50-100' high speed express yachts. They are very efficient and one yacht I ran with them only had 1 % prop slip compared to 15-20% with traditional propellors. BUT, they have a lot of draw backs. If the props are only slightly dirty (like 6 barnacles) they won't get the boat on plane. You need to really know how to run them to optimize their speed. Docking is very challenging. They don't do as well in rough seas. When you're running at cruise and on plane, only 1/2 of the propeller is in the water. They throw a nasty rooster tail behind the boat, usually 30-40' high and 150-200' behind the boat. They're finicky to weight and added weight on the boat. When at slow speeds they're VERY hard on the motors as you're running twice as much propeller as the engines should be spinning (as the entire propeller is submerged) and even turning the steering wheel takes a lot of effort. You'll make the most speed with Arnesons, but they're like a full blown race car, lot's of trade offs in drivability (hard to get on plane, always messing with trim, trim tabs, etc). Here's a pic of a rooster tail of an Arneson yacht I used to run.

https://www.yachtforums.com/th...l.25810/#post-226592

1996 59' Baia with 8v92's, boat is now running 50 mph after the current owner, changed to the new 6 port injectors and had the computers reprogrammed to increase the HP from 760hp to??? .

A friend of mine was stationed on the George Washington many years back and they clocked it at 50 knots, when they were in heavy wind and going with the wind and needed to create enough wind over the flight deck to launch aircraft.