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View Full Version : How do you level a machine on board a ship?



Gary Gill
10-29-2009, 08:23 AM
Just wondering how do you level a machine on board a ship? Would the machine mount to a flat base? This broken leg is giving me time to ponder;-)

Forrest Addy
10-29-2009, 08:54 AM
I've done that. Naturally "level" on a ship varies with trim, wave action, propeller thrust, wind on the upper works, loading, and moments from towing, current while tied up etc. Time to do it is in port on a still night at slack tide when there is no ship traffic. Passage of a major vessel going dead slow three miled away produces enough wave to affect a 30,000 ton grain ship so reading a precision level is almost impossible. Wave reflections from a quay wall five miles away can produce unaccountable motion. Frequent phone communication with the anchor watch and the port captain's office will allow you to time sensitive operations to windows of opportunity. You really do need flat water if the machine tool is sensitive to leveling. Then again the accuracy reqired of the machine tool may not warrant the finest degree of leveling and alignment.

A machine tool's foundation in the ship has to be designed to minimise the effect of ship deflection on the long axis alignment. Many ships deflect amazingly from wave action - more then enough to throw a bind in a lathe carriage if the lathe is larger like a 24" or so and its foundation attached to more than one frame.

Most machne tools don't really require levelng because they are intrinsically stiff - a knee mill, ram shaper, or vertical boring mill for example. So long as you don't put a bind in the machine's structure when bolting it down to the foundation the machine will perform within specs. Longer machine tools like lathes and planers and those with shallow beds like HBM's require sturdy fabricated foundations designed to hold the machine in a single plane by means of a box under structure or a three point attachment to the ship's structure.

An effective machine shop can be installed in a ship without undue fuss and feathers but the issue of deflections and whether the shop is to be used at sea in a storm (when else do you desparately need machine shop services) very much depends on the marine architect's foresight.

Leveling (actually installation to ensure correct alignments of all the machine's axes of motion and rotation) progresses on board ship in much the smae manner as on dry land except for the far greater flexibility of the machines foundation. Most ships I've been on are flexible enough to register my shifting weight on the level's vial as I moved around in the course of my work. You may have to select a single place to stand in a position to observe the level as it's placed here and there.

Outside of that's it's amatter of following the installation instructions.

Ken_Shea
10-29-2009, 08:54 AM
Just wondering how do you level a machine on board a ship? Would the machine mount to a flat base? This broken leg is giving me time to ponder;-)

Me thinks you are pondering too much already :D

Evan
10-29-2009, 09:02 AM
Use a laser or piece of wire. It's true that matters, not level.

Randolph
10-29-2009, 09:28 AM
This doesn't address the question directly as Forrest's answer has done but it is connected. There was a Lehman Hydrotrol 20" lathe in the machine shop aboard the ship I served on in the late 1950's. It was a hefty machine and gave me a lot of early experience.

As a matter of curiosity I mounted a dial indicator on the tool post and placed the button against the OD of the chuck while the ship was rolling in fairly heavy seas. The indicator showed a movement of .003" as the ship twisted and rolled. There would likely have been misalignment of up to more than .100" had I taken readings at the end of the 6 foot lathe bed. The machine shop was located on the main deck level of the ship.

JCHannum
10-29-2009, 09:56 AM
Another method of alignment, not relying on use of a level is the King way aligner. It is discussed in this thread from PM.

http://www.practicalmachinist.com/vb/showthread.php?p=853056

rkepler
10-29-2009, 10:18 AM
Another method of alignment, not relying on use of a level is the King way aligner. It is discussed in this thread from PM.

http://www.practicalmachinist.com/vb/showthread.php?p=853056

The King Way aligner has level bubbles.

http://www.kepler-eng.com/images/kingway.jpg

fortcollinsjerry
10-29-2009, 12:41 PM
Level is in the eye of the beholder. There is a early model submarine on perment display in Portsmouth New Hampshire (the Albacore) with a lathe welded perpindicular to the bulkhead about four feet off the floor. The docent conducting the tour claims that it actually works and that parts were made under way as part of the early sub devcelopment. Pretty interesting story.

philbur
10-29-2009, 01:02 PM
You put it on pontoons and float it on the ships swimming pool. Well all the ships I've been on had swimming pools.

Phil:)

AD5MB
10-29-2009, 01:39 PM
I worked in a shipyard. You carry a level on a ship once. just once. you hear about it until you die. no, it wasn't me.

Evan
10-29-2009, 02:32 PM
You put it on pontoons and float it on the ships swimming pool. Well all the ships I've been on had swimming pools.


The Russian Typhoon class boats have a pool. :D

http://ixian.ca/pics6/pool.jpg

Oldbrock
10-29-2009, 02:59 PM
You want to install a large lathe on a ship you bolt it down to a 4' thick chunk of reinforced concrete insulated from the ship with 4" of styrofoam. Level is something you ignore aboard ship. Straight and true, on the other hand, is of extreme importance for a precision machine tool. My Starrett level is something I would sell if I was signing up for machining duties aboard ship. Peter

Gary Gill
10-29-2009, 05:18 PM
Interesting replies.

x39
10-29-2009, 05:45 PM
I have to admit that the idea of running a large lathe in any kind of a sea doesn't hold much appeal to me. Cripes, it's hard enough keeping your appendages safe when the floor isn't moving.

The Artful Bodger
10-29-2009, 06:27 PM
Well that was quite a disappointment, I was hoping to learn how I could level the billiard table on my yacht.:D

JMS6449
10-29-2009, 06:42 PM
On the Coast Guard 327' class of cutters the 13" SB was mounted on the main deck. Headstock just forward of the bulkhead between the engineroom and fireroom with the tailstock 5' forward of that, perfectly amidship on a solid steel plate but not sure how it was attached to the frames.

No problem using it in 10'-15' seas, you just need to be salty. I remember turning new bolts to fasten the hawes pipe covers. Cut 3/4 or 7/8 fine threads in monel with those conditions.

The USCGC Taney WHEC-37 is on display at the inner harbor in Baltimore.

On board 6/73 - 1/75

"Semper paratus"

gda
10-29-2009, 07:54 PM
The two benefits that I have read about for having a machine level are:

1) So that you can use a level for quick set-ups of odd workpieces (obviously not for high precision)
2) So that lubrication will distribute evenly in the ways.

On a ship - straight and true are all you can do.

philbur
10-29-2009, 08:55 PM
I think the main reason for levelling a lathe is that it is a convenient way to check that the bed is not twisted. If the lathe is small enough that it's own weight will not cause any unacceptable deflection then it will remain untwisted no matter what happens to the deck or orientation of the ship as long as the machine is not rigidly bolted to the deck. For a larger machine that cannot support its own weigh with out unacceptable deflection then I think Peters idea of mounting it on a stiff 4ft thick concrete base that is not rigidly attached to the deck is the best solution. Providing you can prevent the deflection of the deck being transmitted to the machine the angular orientation of the machine is unimportant, it could be mounted on the wall in a force nine and still perform perfectly acceptable work.

Phil:)

jmm360
10-29-2009, 09:40 PM
You want to install a large lathe on a ship you bolt it down to a 4' thick chunk of reinforced concrete insulated from the ship with 4" of styrofoam.

Is this chunk of concrete (4' thick??) with a lathe bolted to it on styrofoam supposed to sit there and behave itself when they hit some weather?

Doc Nickel
10-29-2009, 09:57 PM
The Russian Typhoon class boats have a pool.

-And if you look elsewhere on that guy's series of photos, you'll find a couple shots of the Typhoon's lathe. I wonder if the Russian flunky giving the tour would know how they levelled it? :D

Doc.

TGTool
10-29-2009, 09:57 PM
Most ships I've been on are flexible enough to register my shifting weight on the level's vial as I moved around in the course of my work. You may have to select a single place to stand in a position to observe the level as it's placed here and there.


... And then paint the pair of foot silhouettes on the deck where the operator is to stand while operating the machine? :D

Don Young
10-29-2009, 11:16 PM
I am pretty sure that Sheldon lathes used a three point mounting in the Army's mobile (truck mounted) machine shops.

rdfeil
10-29-2009, 11:42 PM
I don't know the answer to the OP's question but, my 1951 LeBlond was a Navy machine and it has a 3 point mounting system. The machine is a 17 X 36 sliding gap. The headstock end has a standard 2 point mounting with leveling screws. The tail stock end is a single foot centered under the bed and it has a 4 leveling screws and the mounting to the bed is a pivot point in-line with the bed. I was told this is to eliminate twist in the bad as the ship torques. I don't know if this is true but on my concrete shop floor it leveled up nicely and doesn't seem to twist at all :D .

lazlo
10-30-2009, 07:29 AM
Most ships I've been on are flexible enough to register my shifting weight on the level's vial as I moved around in the course of my work.

I think the answer is that you level the lathe as best you can while at port, and just deal with it at sea. Like Forrest says, the whole ship is a twisting wet noodle, so you're not going to be doing precision tool and die work in rough seas.

Evan
10-30-2009, 08:12 AM
I used to service equipment on the Canadian destroyers. Frequently the copiers they used were in the machine shop compartment. The lathe was usually just bolted down to weldments on the deck with means to adjust the mounting points. The copier on the other hand actually does need to be level to operate correctly. That of course was a lost cause on a ship and it would cause problems with developer powder spillage. On one ship I had a call to find when I arrived that in rough seas the machine had leapt off the top of the filing cabinet that it was screwed to and had subsequently bounced around the compartment for an undetermined amount of time. It was broken.

J Tiers
10-30-2009, 08:30 AM
I worked in a shipyard. You carry a level on a ship once. just once. you hear about it until you die. no, it wasn't me.

Interesting.... before it is launched you might.... with a wedge the name of which I forget, to compensate it for the slope of the launching ways. At least so I am told, not having worked building ships.

deeman
10-30-2009, 10:52 AM
There is one thing about building boats....if carrying a level is useless...the next most useless tool for building must be a square.A carpenter works by inches,a machinist by thousands and a boatbuilder by eye.Now how that applies to a machineshop on a boat is anyones guess.

mototed
10-30-2009, 01:23 PM
bounced around the compartment for an undetermined amount of time. It was broken.
You think! :D Gota love those kind of service calls.

philbur
10-30-2009, 02:43 PM
I think it is not diffcult to restaint that big chunk of concrete without having to rigidly fix it to the vessel's structure.

Phil:)


Is this chunk of concrete (4' thick??) with a lathe bolted to it on styrofoam supposed to sit there and behave itself when they hit some weather?

Evan
10-30-2009, 02:58 PM
I think it is not diffcult to restaint that big chunk of concrete without having to rigidly fix it to the vessel's structure.


I haven't been on a warship at sea but my son has. From what he tells me if it isn't bolted down it isn't going to stay where it was put. They don't slow down for little 20 foot swells. He tells me it's like driving across railroad tracks without the benefit of a crossing except that it doesn't stop. Even the old hands get sick sometimes.

The Artful Bodger
10-30-2009, 03:37 PM
I used to service equipment on the Canadian destroyers. Frequently the copiers they used were in the machine shop compartment. The lathe was usually just bolted down to weldments on the deck with means to adjust the mounting points. The copier on the other hand actually does need to be level to operate correctly. That of course was a lost cause on a ship and it would cause problems with developer powder spillage.

I think even Captain Cook thought gimbals were old hat.

Evan
10-30-2009, 04:45 PM
They don't waste space on gimbals on a war ship. To mount something like a copier in a set of properly damped gimbals would take up most of the compartment. Gimbals also don't help a bit with the slamming that occurs as the bow broaches each swell. If it breaks like that one did they just requisition a new one.

They have wierd power on those ships. 2 phase 60 volts AC with the hull neutral. Could be for safety reasons, 60 vac won't easily kill you.

jmm360
10-30-2009, 08:52 PM
I think it is not diffcult to restaint that big chunk of concrete without having to rigidly fix it to the vessel's structure.

Phil:)

You can have the job on that ship, I'll stay ashore this time thank you. Been through enough storms to not go anywhere near a ship with that setup onboard.

darryl
10-31-2009, 12:50 AM
I always wondered why they didn't cast pedestals to bolt to the floor and bolt the lathe to. That should prevent the twisting motions that the bottom of the pedestal might be subjected to from making it to the top of the pedestal where the lathe is mounted. This would be like many jewelers lathes are mounted, just on a larger scale.

Evan
10-31-2009, 04:26 AM
Repairs at sea only need to last until they make it to port. Sailors are famous for "lash ups" and "jury rigs".

chief
10-31-2009, 06:33 AM
[QUOTE=lazlo the hole ship is a twisting wet noodle, so you're not going to be doing precision tool and die work in rough seas.[/QUOTE]

Wanna bet.

deeman
10-31-2009, 08:26 AM
http://www.youtube.com/watch?v=qEkErF51Uxg

Now you see the flex inside a ship with the barograph showing things taking a turn for the worse in weather...better be strapped in a chair while you`re working your lathe.

Evan
10-31-2009, 09:11 AM
Here is another reason that everything has to be well secured on a warship. They don't have stabilizers and are rated for hard turns at full speed. This will take the soup pot off the stove in the galley.

http://ixian.ca/pics6/nimitz.jpg

Randolph
10-31-2009, 01:55 PM
Evan, where did you get that photo? I have exactly the same photo on the wall of my shop entitled "97,000 ton Ski-Doo". My son was aboard Nimitz when she was under going those tests.

Teenage_Machinist
10-31-2009, 01:56 PM
What is that? Aircraft carrier?

I agree with doing it by having a heavy pedestal for the lathe, on something soft, and then loosely restraining that. THe huge piece of concrete would have bumpers on it's sides, and then be loosely attached to walls or deck, I guess. Just because it's on styrofoam doesn't mean it can't be on anything else...

Evan
10-31-2009, 01:59 PM
I don't know as I didn't keep track. It's a US gov photo so it is in public domain.

vincemulhollon
11-01-2009, 12:18 PM
You carry a level on a ship once. just once. you hear about it until you die.

You need two levels, two little security cameras and two TV/monitors.

Compare and calibrate the levels against each other so they are "identical"

Then watch both security cams to make sure both levels point the same way at the same time.

Intuitively a larger TV sounds like a good idea because the image is "magnified" but it actually makes it harder to see both levels at the same time.

Tom-C
11-01-2009, 03:50 PM
Yes that is an Aircraft Carrier, specifically the USS Nimitz (CVN-68). Just before they did this, they would announce on the 1MC (general announcing systems): “Standby for heavy rolls!”. Making turns like this (not quite so hard) was part of every Carrier workup.

An Aircraft Carrier can actually turn inside a Destroyer, ask the CO of the USS Belknap when they tried to turn inside the USS John F Kennedy (CV-67) in heavy weather in November 1975.

Evan
11-01-2009, 04:36 PM
My son was on the HMCS Algonquin, an Iroquois class missile destroyer during the RimPac 96 exercise across the Pacific. Those ships have a rear helicopter pad and hanger. The hanger makes them somewhat top heavy so they roll a lot in a power turn. He was at the helm in the Taiwan Straight when they had to do a maximum effort turn to avoid a fisherman with his nets out in the middle of the channel. They had no time to secure, just a few seconds warning. Everybody got dumped out of their bunks and the galley was a mess.

The hanger on those ships is disposable along with the heli inside it. In an emergency if the roll exceeds a critical angle explosive bolts are blown and the hanger is ditched over the side to avoid a capsize. The Canadian ships have an operational mode which I assume all other navies use in which the ship is operated "Without regard for man or machine". That includes such things as running the turbines at absolute max horsepower for the classified top speed of the vessel as well as the maximum turn rate possible without going over. I do know that the Kittyhawk class carriers, while listed as having a top speed of 32 knots can actually do over 40. I won't say how much as I hate black helicopters.... :eek:

loose nut
11-01-2009, 07:10 PM
Back in the '70s I was serving in HMCS Yukon, one of the old River class frigates (I hear she is now part of a reef off of San Diego). We where steaming port side to a pretty rough sea and where rolled to starboard by a good sized wave, the inclinometer read 56 degrees, the point of no return was 60 degrees (a that point there is a 50/50 chance the ship will capsize). Naturally at that particular moment I was going down a ladder facing the starboard side, It got interesting real fast. There where a lot of guys changing there shorts that day.

It was/is routine to walk on the bulkheads of companionways as smaller ships role, you walk on the deck and as the ship roles you step onto the bulkhead and walk as far as you can and then step back onto the deck and repeat he same operation on the other side.

On a lighter note, one night when in a rough sea, the ship rolled to starboard and I heard a thunk. Someone had fell out of his bunk (top one as it turned out) but didn't wake up.In the morning as the duty watch came in, turned on the lights and yelled for everyone to get up we found the guy who had fell, landed in the bottom bunk opposite his with a another guy sleeping in it. Neither of them had woken up. At this point the proper occupant of the bunk was screaming at the trespasser at the top of his lungs, I couldn't understand it ,he was yelling in French but what he was a accusing the guy of was pretty obvious. He took a lot of ribbing for a long time, Innocent or not.

lazlo
11-01-2009, 07:34 PM
Maybe this is a stupid question, but when a carrier pulls a turn like that, how do they keep the aircraft from falling off?

Is that primarily a performance test they do with all the aircraft carefully stowed?

jmm360
11-01-2009, 07:43 PM
Maybe this is a stupid question, but when a carrier pulls a turn like that, how do they keep the aircraft from falling off?

Is that primarily a performance test they do with all the aircraft carefully stowed?

Lazlo, talking out my @ss here cause I've never sailed on a carrier, but i doubt they ever put the rudder hard over with anything loose on board.

Evan
11-01-2009, 08:15 PM
The aircraft are tied down with steel cables to anchor points inset in the deck.

jmm360
11-01-2009, 08:24 PM
What is that? Aircraft carrier?

I agree with doing it by having a heavy pedestal for the lathe, on something soft, and then loosely restraining that. THe huge piece of concrete would have bumpers on it's sides, and then be loosely attached to walls or deck, I guess. Just because it's on styrofoam doesn't mean it can't be on anything else...

Go to sea with something heavy on board that isn't well lashed and report back. Don't mean to be unkind but been there, ships go down and it's lonely,cold and wet out there. RIP good friends.

vincemulhollon
11-02-2009, 11:09 AM
I do know that the Kittyhawk class carriers, while listed as having a top speed of 32 knots can actually do over 40. I won't say how much as I hate black helicopters.... :eek:

I suspect at least 4 knots more, but certainly no more than 10 knots over 40. Just basic physics.

http://en.wikipedia.org/wiki/Hull_speed

Lots of people make a great show of how they know the secret number, but the physical specs are widely available (1069 feet long, 280K HP engines). Traditionally calculated hull speed for that is 44 knots.

Because the power required grows exponentially, the end result doesn't change much if engine power is varied. Double it, maybe you'll go 10% faster, maybe.

Also even the most ridiculous wave piercing hull design doesn't have a length-speed ratio much above 1.5 (compared to the traditional design ratio 1.34). So if you redesigned the hull purely for speed and to heck with all other characteristics (unlikely), you might crank it up to the upper 40s, at absolute best.

That's the very non-top secret math of it.

There is a machining lesson in this, in that doubling power to a 1/4 inch endmill from 1/8 HP to 1/4 HP increases production by a much higher percentage than doubling from 100 to 200 HP on the same 1/4 inch endmill. Different limitations and scaling factors come into play in certain ranges etc.

Evan
11-02-2009, 01:11 PM
Lots of people make a great show of how they know the secret number, but the physical specs are widely available (1069 feet long, 280K HP engines). Traditionally calculated hull speed for that is 44 knots.


A few percent makes a big difference in a stern chase as my son found out on manoeuvres with the Kitty Hawk.

derekm
11-02-2009, 06:33 PM
Hmm stern chasing a carrier - the thing that does that for a living has complicated toilets and the users wear film badges

boslab
11-02-2009, 06:47 PM
why would you try to level a machine on a movable platform?
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