# Ullage Plug Explanation Needed



## PAUL XAVIER

Hello,
May anyone here please explain what an ullage plug is?
TY (Cloud)


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## IRW

An Ullage Plug. Is a plug on the top of a tank, usually screw, which give access to the tank containing a fluid cargo allowing the distance from the top of the tank to the fluid be measured. Then tables for the tank(s) with temperature corrections will give the volume. Used them on Bank boat deep tanks to take ullages and temperatures. Hope this helps. IRW


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## Mariner44

Discharging crude on the British Beacon, which had a pressurised inert gas system in operation, I removed an ullage cap just at the moment the surface of the crude oil touched the bottom end of the ullage pipe. The result was just like an oil-strike - a fountain of oil spray of about 30 feet in the air. I spent the afternoon with rags and paraffin clearing up the mess!


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## PAUL XAVIER

TY for the replies IRW and MARINER44. 
@IRW .Is ullage plug similar to hatch cover? ,because you said it provides access to the tank.


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## NoR

I've never heard the term 'ullage plug' before, the caps that screwed onto the top of sounding pipes were just called 'caps'.
I worked for a short time on an Amercan registered supply boat and they sounded tanks using a plug which roughly fitted the diameter of the sounding pipe. The base of the plug was concave and you could feel when it hit the top of the liquid in the tank, it was attached to a sounding tape.
Never come across it since.


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## Wilco

In tankers, in my day, each cargo tank had an ullage plug. This, usually is a pipe standing about 12ins proud of the deck. The aperture of this pipe is about 4ins in diameter & usually , when not in use it is closed by means of a screw down metal cap .When loading or discharging, by means of a tape with a float attached, or when getting nearly full by means of a calibrated ullage stick inserted through the ullage plug the level of the oil can be established. From this measurement, using the appropriate tables, making due allowance for temperature, the volume of oil in the tank can be calculated thus the speed of loading/discharging can be established also enabling the tank to be shut off when the ullage is at the level previously calculated in the cargo planning.
I think that in the present day everything is computer controlled.
Hope this helps.


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## kewl dude

US Flag ships I sailed they were called sounding tubes. 

http://www.wosupply.com/index.php/products/marinespecialtyvalves

Attached from the above site:

MAIN_SOUNDING_TUBE.jpg (144.2 KB) 
SOUNDING_TUBE_EXP_VIEW.jpg (96.2 KB)

Typically they usually were mostly used on cargo and bulk ships with double bottom fuel oil storage tanks. They were also used in machinery and other enclosed spaces but with a spring powered self closing gate valve with a pipe thread on top to accept a plug if needed. 

The top of the sounding pipes were on the open deck or perhaps in a resistor house on the main deck and plugged with a sounding tube bronze threaded plug. The plug had either a centered square recessed opening to match a wrench used to loosen them or a slit not unlike that for a straight blade screwdriver. 

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

Attached: UllageTape.jpg (116.4 KB)

When sounding double bottom tanks, that typically were six to eight feet high, reached by a long pipe from the deck to within a few inches above the bottom of the tank. Typically a steel striker plate was installed beneath the sounding pipe. This is a picture of an expensive 1/2 inch x 50 feet tape. Which for most of the cargo ships I sailed would be too short. The tape has to be long enough to reach from the deck to the bottom of the tank.

http://www.brighthubengineering.com...ry/35372-sounding-the-tanks-of-a-ship/#imgn_4

http://tinyurl.com/ullage

The bottom of the measuring tape has an attached brass bobber. When measuring light liquids typically the bobber would have a pointed end. When measuring thick substances like ships bunker C fuel oil the bobber had an open hollow cup shape on the bottom of the bobber.

Ullage refers to measuring the space ABOVE the liquid level in a tank then using charts provided by the ship builder to determine tank liquid contents.

So you remove the plug and typically wrap it in a small rag and put it in a back pocket of your boiler suit so you do not lose it. Inserting the bobber into the top of the sounding tape you flip over the tape cranking handle and let it fall free. 

Listening closely you will hear a 'plop' when the cup hits the top of the liquid perhaps fifty or more feet below and the tape will go slack. Then by quickly pulling up while listening for the 'plop' and gently letting down you get a feel for when the bobber is sitting lightly atop the thick oil. Read the measurement on the sounding tape where the tape is level with the top of the sounding tube and also the deck.

Light liquids like water were measured by rubbing blue chalk on the bottom portion of the measuring tape where the liquid surface is to be expected. Then dropped to the bottom of the tank, then when pulled up the liquid level will be clear. The lighter blue of the dry chalk on top with the now dark blue wet chalk below.

Sounding tapes were used when taking bunkers and just prior to arrival in a port. Some ports wanted to know everything in the way of potable and ballast water, ships fuels and lubricating oils we carried upon arrival. Regardless this information was called for in our log books.

Greg Hayden


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## John Rogers

Plain and simple its a Dip Stick Hole. just like checking the oil level in you cars engine.


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## Stephen J. Card

Used a temporary 'plug' when using an ullage tape when level of the liquid is lower the end of the dipstick.

Easy down on the inert gas or it will just blow too much out. Open the screw down the cover and swing over. Then we had temporay plug' a wooden plug... just to fit over the ullage port. The linen tape passed through a thin slot in the wooden plug. Lower away with the cork float and you were done.... no gas spraying... no fumes.... or at least not too much. Also stopped the float swinging about in calm atmosphere. On side top wing tanks....OBO... the worst. the tanks were relatively small and if you got of gas swirling inside it would definitely cause a gusher. Then short dip sticks. The big dip sticks for the big main hold tanks were about 18 feet long. 

Nah... OBO's were nastly things. Reefers.... have you ever seen when it goes wrong.... you got to find where that blo*ody yellow banana come from! 

Stephen


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## John Cassels

Wilco said:


> In tankers, in my day, each cargo tank had an ullage plug. This, usually is a pipe standing about 12ins proud of the deck. The aperture of this pipe is about 4ins in diameter & usually , when not in use it is closed by means of a screw down metal cap .When loading or discharging, by means of a tape with a float attached, or when getting nearly full by means of a calibrated ullage stick inserted through the ullage plug the level of the oil can be established. From this measurement, using the appropriate tables, making due allowance for temperature, the volume of oil in the tank can be calculated thus the speed of loading/discharging can be established also enabling the tank to be shut off when the ullage is at the level previously calculated in the cargo planning.
> I think that in the present day everything is computer controlled.
> Hope this helps.


Calibrated ullage stick / - the well known "Jesus "stick ?.


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## johnar

Hi all, On my boat I use a suitably marked varnished piece of dowel to sound the level and therefore the amount of fuel diesel available.On sunny days in particular however it is difficult to read the level accurately. What substance can I use on the stick,when sounding, to overcome this without risk of contamination to the fuel,my regards to all readers---roger--


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## Sebe

The calibrated stick was called a 'crucifix' on the tankers I sailed on


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## alastairjs

Roger,
We sometimes had the same problem, particularly with light refined products, on tankers back in the day. We used to rub the ullage stick with blackboard chalk before taking a reading, worked a treat, no contamination. Our ullage sticks were painted black with white graduations, easier to see the oil level.
Regards,
Alastair


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## johnar

Thank you Alastair,my regards to you--roger--


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## Robert Bush

*ullage plugs*

They are distinct from sounding pipe caps, much heavier about four inch diameter threaded and sometimes with a neoprene washer.

Before inert gas in tankers when loading a sandbag was placed on top of any open plugs.

Topping off light oils to a certain ullage using ullage sticks and chalk could be hazardous especially if there was no wind. You stood on the windward side if ther was any. There were cases of deaths due to breathing fumes more often among cargo inspectors who were alsways in a hurry.

When ullage plugs were located in the center castles there were some serious casualties. One was on a Shell tanker, a D class vessel if I remember correctly.

Ullage plugs were also used to measure innage or the R O B remains on board after discharge using a metal tape with a brass bob and water finding paste.

Disputes on this figure were common and were argued over the "Retention Clauses " in the charter party. The sums involved could be large on a big tanker.


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## Jose Manuel Ortega

On my early days in tankers, early 70´s, I was carring my " cross", also above called a 'crucifix'. It was a thousand tons domestic tanker. At the end of my sea life, in 300K tons tankers, cargo system was " enclosed ", that means always under IG pressure. The way to measure the level of liquid was as per attached picture, except that the pipe inside the tank does not exist, the sensor goes down vertically free.


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## Dickyboy

The "Ullage" is the distance between the top of the liquid in the tank and the inside side (Obviously) of the top of the tank.
The Ullage Pipe was usually placed near the lowest point of the tank during cargo operations, a point where you could sound the final few inches of the cargo, that even a Wessoe Gauge couldn't read.
I also got caught out by cracking open the lid, and the IG forced the oil out with great force all over the fore end of the accommodation.


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## david freeman

PAUL XAVIER said:


> Hello,
> May anyone here please explain what an ullage plug is?
> TY (Cloud)


 iF MY MEMORY SERVES ME CORRECTLY an ullage pipe on a bunker, settling tank of ballast tan went from top to bottm of the tank save for the last 4inches, and then one had a bottm of footplate on the tank floor to protect the steel of the tank membraine. 
In IG tankers this ullage pipe for crude oproducts had the same ullage pipe but about 6inches below the deck head holes were drilled to allow the IG to escape up the ullage pipe when the ullage plugs were removed( This was also truue for bunker and settling and water/ballst Fresh and seawater tanks), to either use the dip tape or ullage sword( From open loading days), so preventing a gusher to escape?
All heresay you understand, I am only a er waller not a deck officer, with gold braid?
This was all superceded by automatic ullage floats and recorders: However I still believe in times of crisis when the ullage flaots did not work, one reverted to ullage pipes and swords and dip tapes.(Frogger)(POP)(Thumb)


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## Farmer John

The use of Ullage measurements, I did them for about 5 years on a wetland nearby. We augered holes into the peat, and then used the blackboard paint and chalk for quite a bit, the someone gave us an electronic buzzer on a tape (Thanks, EA).

In wetter Winters, and even Summer times, we got -ve results, not what you would want at sea.


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## Halcyon

Reading these threads brings back memories. I remember using "Whessoe" gauges to find the ullage and also for "topping off".I was always wary of relying on the mechanical gear. I was brought up with the crucifix in the ullage cap, oil fumes in your face, slowly getting pissed and the Mate ordering me off the deck in case the "old man" heard that the cadet was drunk!!.Happy days!!!


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## spongebob

Always knew them as sounding pipes

Bob


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## Frank P

On the M/T Hallanger we had two ullage pipes, the main one on the deck and an inspection/ullage opening in the tank hatch cover, you can see them in the photo below. We used the "cross sick" in the one on deck and the "tape measure with float" in the one on the hatch cover..

http://www.shipsnostalgia.com/gallery/showphoto.php/photo/6863/title/m-2ft-hallanger/cat/503

Cheers Frank


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## matthew flinders

Wilco said:


> In tankers, in my day, each cargo tank had an ullage plug. This, usually is a pipe standing about 12ins proud of the deck. The aperture of this pipe is about 4ins in diameter & usually , when not in use it is closed by means of a screw down metal cap .When loading or discharging, by means of a tape with a float attached, or when getting nearly full by means of a calibrated ullage stick inserted through the ullage plug the level of the oil can be established. From this measurement, using the appropriate tables, making due allowance for temperature, the volume of oil in the tank can be calculated thus the speed of loading/discharging can be established also enabling the tank to be shut off when the ullage is at the level previously calculated in the cargo planning.
> I think that in the present day everything is computer controlled.
> Hope this helps.


 Also used for taking temperatures, at various depths, and specific gravities.


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## Jose Manuel Ortega

In old days, measuring in tankers was done with tapes through the opening manhole in the hatchcoaming, while for topping off we used the cros sor crucifix. Taking about late 60´s and 70´s.
First time I used MMC sounding tape was on 85. MMC stand for the french maker of this device. 
http://www.bing.com/images/search?q=mmc+sounding+tapes&qpvt=mmc+sounding+tapes&FORM=IGRE#a
Tankers are, from some years ago, a “ enclose space “. Therefore the only way to manage the levels, samples, temperatures etc., is with the MMC or similar device. The MMC is able to recognize even 1 cm of water
On deck the hole is as per attached MMC plug 1A and the MMC device as per MMC sounding tape 2A. 
The tape is going down the tank free fall. At the beginning they fix a soung pipe to the bottom, but, even holed, there were at times small overflows.
From the Cargo Control Room, you control the level of the oil while loading/discharging with remote radar control, different makers.
On the 70´s I was working in T2 tankers, open system, loading benzene and all kinds of zene´s, pure chemicals, with the cross.
From 85 all enclose system.


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## japottinger

A Swire company I worked for a few years in Greenock constructed deck tank hatches, oval, round in carbon, Colclad or stainless steel for numerous shipbuilders in UK and abroad for crude, product and chemical tankers . Most had an ullage port set into the domed or flat lid, this had a short tube extension about about 8ins diameter with hinged lid and dog clamps.


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## Split

Wilco said:


> In tankers, in my day, each cargo tank had an ullage plug. This, usually is a pipe standing about 12ins proud of the deck. The aperture of this pipe is about 4ins in diameter & usually , when not in use it is closed by means of a screw down metal cap .When loading or discharging, by means of a tape with a float attached, or when getting nearly full by means of a calibrated ullage stick inserted through the ullage plug the level of the oil can be established. From this measurement, using the appropriate tables, making due allowance for temperature, the volume of oil in the tank can be calculated thus the speed of loading/discharging can be established also enabling the tank to be shut off when the ullage is at the level previously calculated in the cargo planning.
> I think that in the present day everything is computer controlled.
> Hope this helps.


"12ins proud of the deck". That seems to be an uncomfortable way to load/discharge a ship. I worked on T2s. The ullage plug was situated on top of the tank lid. We used to cover them with mesh flame screens when we were not peering into them. We, also, covered them with a rag to see whether we had a good suction. The lids were about 3-4 feet above the deck, which was a convenient height to see what was going on when cargo handling.


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## Steve Oatey

johnar said:


> Hi all, On my boat I use a suitably marked varnished piece of dowel to sound the level and therefore the amount of fuel diesel available.On sunny days in particular however it is difficult to read the level accurately. What substance can I use on the stick,when sounding, to overcome this without risk of contamination to the fuel,my regards to all readers---roger--


Try " Kolor Kut "


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## lakercapt

I was only on old tankers and the ullage cap was on the tank access lids.
We used a crucifix stick with chalk to see how much ullage there was when loading. On my first trip on a tanker I foolishly kept looking down the ullage hole to see how the cargo was coming in.
Result was I got totally pi$$ed from the gasses that were shooting out the hole. The hangover was wicked


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## luigi

The earlier BP Tankers I was on, the 'Birdie' and Tree classes had ullage pipes, which as has been said were around 4 inches diameter.

They were different to sounding pipes which were only around 2 inches in diameter. Sounding pipes were generally used on water tanks and bunker tanks and, as the name suggests, you used to sound them - i.e. measure the depth of liquid in the tank, whereas the ullage pipes were located on the cargo tanks and you used to measure the ullage or the distance from the top of the pipe to the surface of the cargo.

The ullage caps were made of brass and very heavy. They had a wide cross machined into the top of them for screwing/unscrewing. During loading or discharging the caps were kept well away, because the pipes were the only means of venting, so the last thing you wanted was a cap screwed in!!

During loading we used to put a sandbag over the pipe, which acted as a crude (as in rudimentary) pressure relief valve. During discharging, we used a gauze disc, reinforced with a brass ring around the outside as a vacuum breaker/spark arrestor.


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## sidsal

In the far off days in tankers we used the chalked rods to establish the ullage. We carried perhaps five or six different things and she loading several at a time it was quite a task to keep an eye on things. Geysers were quite frequent.
On the cargo ships in Brocklebanks the brass screw-in caps of the sounding pipes were removed when approaching the Suez Canal and replaced with wooden plugs. Otherwise the Gypposwould steal the caps (and anything else).
On one ship I was in the emergency binnacle on the poop fell over when we cleared theG of Aden and the ship started rolling. They had stolen the long brass screwed pins holding it down


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