# How to test cock



## zebedee (Dec 19, 2010)

In 1959 I was sitting my oral examination as part of the process necessary to qualify for my Second's Ticket: or, more officiously I was undergoing my Viva Voce as part of my Engineering Knowledge examination to qualify for my Board of Trade Certificate of Competency (Motor) Second Class. One of the questions was along the following lines "you have just taken over the watch and you find that there is no water showing in the boiler gauge glass, what action would you take?"
Obviously the first thing to do is to demonstrate that I know the correct systematic procedure for blowing through the water glass! However this only proved that the glass was indeed choked: so I suggested using the test cocks. The sniffy reply was "We don't think much of those." So I took the only course open to me: extinguish the fires and utilise the easing gear. With hindsight it was a good job he did not follow up on the test cocks since quite clearly the output of each test cock will be steam: so how do you tell them apart? When I joined my nrxt ship I was instructed to replace the gauge classes in the boiler and I took the opportunity to utilise the test cocks and examine the output in. Each pipe produced a conical jet of steam as one would expect; but the steam cone was a short fat one while the water cone was much more obtuse. The conical angle of the steam was about 20° while the water cone was about 45°. I assume that the water having a higher density than the steam was less dispersed by the air into which it discharged.
I have never had to put this arcane knowledge into use and as I have not been practically involved in Marine Engineering for 50 years it is very unlikely that I ever shall.
Lionel


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## John Briggs (Feb 12, 2006)

I knew a girl in one port who was extremely good at testing cock!


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## endure (Apr 16, 2007)

John Briggs said:


> I knew a girl in one port who was extremely good at testing cock!


I was waiting for something like this to appear (Jester)


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## Chris Isaac (Jul 29, 2006)

And you didn't have to wait long!
I don't really know what else you would expect?
At our ages smutty humour and innuendo are about all we have left.
I shall now go and give mine a jolly good testing and see if I can get a "conical jet of steam".
I shall report back the results.


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## Gulpers (Sep 8, 2005)

Chris Isaac said:


> I shall now go and give mine a jolly good testing and see if I can get a "conical jet of steam".
> I shall report back the results.


Chris, if that was successful, it would be worth posting it on YouTube! (Jester)


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## Farmer John (Feb 22, 2012)

Gulpers said:


> Chris, if that was successful, it would be worth posting it on YouTube! (Jester)


But please spare us any photos.


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## spongebob (Dec 11, 2007)

Never mind the cock testing, it is the blowdown that is the problem at our ages.

Bob


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## ART6 (Sep 14, 2010)

zebedee said:


> In 1959 I was sitting my oral examination as part of the process necessary to qualify for my Second's Ticket: or, more officiously I was undergoing my Viva Voce as part of my Engineering Knowledge examination to qualify for my Board of Trade Certificate of Competency (Motor) Second Class. One of the questions was along the following lines "you have just taken over the watch and you find that there is no water showing in the boiler gauge glass, what action would you take?"
> Obviously the first thing to do is to demonstrate that I know the correct systematic procedure for blowing through the water glass! However this only proved that the glass was indeed choked: so I suggested using the test cocks. The sniffy reply was "We don't think much of those." So I took the only course open to me: extinguish the fires and utilise the easing gear. With hindsight it was a good job he did not follow up on the test cocks since quite clearly the output of each test cock will be steam: so how do you tell them apart? When I joined my nrxt ship I was instructed to replace the gauge classes in the boiler and I took the opportunity to utilise the test cocks and examine the output in. Each pipe produced a conical jet of steam as one would expect; but the steam cone was a short fat one while the water cone was much more obtuse. The conical angle of the steam was about 20° while the water cone was about 45°. I assume that the water having a higher density than the steam was less dispersed by the air into which it discharged.
> I have never had to put this arcane knowledge into use and as I have not been practically involved in Marine Engineering for 50 years it is very unlikely that I ever shall.
> Lionel


I had a very similar question to that during my orals. The question was "The gauge glass water cock is blocked. What do you do?"
I went off on an explanation from my studies of how I would close both cocks, unscrew the test plug from the water one, insert a clearing plug (apparently a long length of rod with a screw thread on the end), insert it, open the cock, screw the clearing rod in, withdraw it, close the cock....etc. etc.
The BoT examiner of engineers listened patiently until I had finished, then said "Correct. Have you ever seen one?"
"Um...Well no Sir."
"So how do _you_ do it?"
Somewhat chastened I muttered "I get a welding rod, close the cock, take out the bung, open the cock and stuff the rod up it with a pair of pliers."
"Then why didn't you say so in the first place? Next question."

Very practical guys, those examiners in those days!


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## chadburn (Jun 2, 2008)

ART6 said:


> I had a very similar question to that during my orals. The question was "The gauge glass water cock is blocked. What do you do?"
> I went off on an explanation from my studies of how I would close both cocks, unscrew the test plug from the water one, insert a clearing plug (apparently a long length of rod with a screw thread on the end), insert it, open the cock, screw the clearing rod in, withdraw it, close the cock....etc. etc.
> The BoT examiner of engineers listened patiently until I had finished, then said "Correct. Have you ever seen one?"
> "Um...Well no Sir."
> ...


Making sure you stand to one side. Test Cocks are fine as long as you keep testing them otherwise they also get choked up and become of little use in an emergency situation.


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## trotterdotpom (Apr 29, 2005)

John Briggs said:


> I knew a girl in one port who was extremely good at testing cock!


Art6 was tested orally but it's not clear whether or not he passed.

John T


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## trotterdotpom (Apr 29, 2005)

Art6:".....Somewhat chastened I muttered "I get a welding rod, close the cock, take out the bung, open the cock and stuff the rod up it with a pair of pliers."

I went to that clinic too, Art. 

John T


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## Steve P (May 23, 2007)

Story I was told many years ago, which could be true but proably not.

Boiler gauge glass is blocked, what do you do?
Use the other gauge glass!

What if that is blocked?
Use the test cocks!

What if they're blocked?
Use the other test cocks!

Where are you getting all these test cocks from?
Same place you are getting all these bloody blockages!

Get out. Come back in 6 months.....!!


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## Varley (Oct 1, 2006)

Steve P said:


> Story I was told many years ago, which could be true but proably not.
> 
> Boiler gauge glass is blocked, what do you do?
> Use the other gauge glass!
> ...


If true plagiarised from the Deck.

You are at anchor and the wind starts to get up what do you do?

Put out more cable.

The wind gets up some more, do you take further action?

Yes, put out more cable.

.......... some recitative further ............

Where are you getting all this cable?

Same place you're getting all the wind!


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## A.D.FROST (Sep 1, 2008)

Gauge Glass cocks are the only v/v's with cast handle that do not indicate direction of flow(beware)


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## Tony Morris (Oct 7, 2006)

Was there not a 2nd gauge glass? all boilers I have been with had 2 as a check.
My ticket says "Motor" and I would prefere to keep away from steam as I have a nasty habit of getting burnt with the damn stuff. As soon as the MARPOL sulpher fuel level is reduced to 0 the better for me, then we can run on only gas oil with no need for a boiler.

Tony


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## Pat Kennedy (Apr 14, 2007)

I believe it was a blocked test cock on a torpedo tube that was instrumental in the sinking of the submarine Thetis, on sea trials in Liverpool bay in 1939


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## howardws (Aug 15, 2009)

Great Western Railway locomotives were / are fitted with only one gauge glass and a set of test cocks. We blow the gauge glass cocks through at the start of each duty and hope to goodness we don't need to use the test cocks! A get you home solution is to fill the boiler until the loco primes slightly and to keep it that way!


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## sidsal (Nov 13, 2007)

As a non engineer I remember an engineer's tale about the junior engineer who summoned his Chief to say he thought the safety valve was stuck. Chief comes down and looks at the huage and says - " It's OK - the needle is barely in the red"
Junior says - " It's the second time around though"!!


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## chadburn (Jun 2, 2008)

The problem with test cocks like the salinity test cock was the concern that the whole thing would come away from the Boiler whilst you were trying to open it with a short length of pipe!!
A question for the Engineers who may have served on vessels with the older type of gauge columns. 'What else were the choke clearing holes used for?


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## berbex (Feb 17, 2013)

Quoting Art6 ""I get a welding rod, close the cock, take out the bung, open the cock and stuff the rod up it with a pair of pliers."

Then when the rod penetrates the blockage, out comes the effluent, hits the pliers and splashes everywhere, mostly in the face of the one holding the pliers. I've seen similar done and it was ugly. The last thing the fellow would think of is closing the cock again.

Some practical ideas are no better than a loose fire-cracker.


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## chadburn (Jun 2, 2008)

berbex said:


> Quoting Art6 ""I get a welding rod, close the cock, take out the bung, open the cock and stuff the rod up it with a pair of pliers."
> 
> Then when the rod penetrates the blockage, out comes the effluent, hits the pliers and splashes everywhere, mostly in the face of the one holding the pliers. I've seen similar done and it was ugly. The last thing the fellow would think of is closing the cock again.
> 
> Some practical ideas are no better than a loose fire-cracker.


Tackling a blockage is like putting a lighted torch to ignite a burner, stand to one side(Thumb). However, on the old type of gauge column before pre formed packing a rod was required through both the body and valve to keep the holes in line in order to pack the body and end glands with blue asbestos graphite mixed fibre which was pressed into place using a copper packing tool followed up by the gland nuts. A dangerous business picking up the blue asbestos with the fingers and as Art indicated nobody mentioned it at the time.


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## berbex (Feb 17, 2013)

Agreed.

The subject of this thread was posted, I suspect, somewhat tongue-in-cheek (no pun intended here) and perhaps from behind a veil of innocence. Nothing out of the ordinary.

It used to happen when i was young. But there used to be some good soul who would see through my naivety and make sure I got it right and avoid embarrasment or worse, injury. Just to make sure, don't try it.

And yes I have seen burner lighting occasionally, and old navy hands who were overconfident mainly, getting their eyebrows savagly trimmed, and after shoving out of the way the guy behind him peering right into the furnace (like yours truly).


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