Question

[Brian Hawley]

Here is a question I received from my web site. I have no idea how to answer it off the top of my head. I figure it might have been the fellow in question was not even a part of O's crew. Perhaps he was an outside vendor. Still I thought I would post it here and see if anyone has an answer. By the way what is a Kelvin's Patent Testing set? I tried lookoing it up on the web and found nothing from a very quick search.

Brian


Email follows:


I hope this is not an unwelcome intrusion. I got your e-mail address from your website.

I am researching a Kelvin's Patent Testing set which was used on the Olympic. The "asset card" which accompanies the instrument is signed by A. E. Henderson C.R.O.and dated 1913.

I wonder if you know where I can get information about the Olympic's crew list, in particular this man relative to this date.

Many thanks and kind regards
Ray

 

[Mark Chirnside]

Regarding the crew list --

The list for 1913 is either:

BT 100/253 Ship's Name: OLYMPIC 1913 Mar. - May
BT 100/254 Ship's Name: OLYMPIC 1913 May - July
BT 100/255 Ship's Name: OLYMPIC 1913 July - Aug.
BT 100/256 Ship's Name: OLYMPIC 1913 Sept. - Oct.
BT 100/257 Ship's Name: OLYMPIC 1913 Oct. - Nov.
BT 100/258 Ship's Name: OLYMPIC 1913 Dec. - 1939

1939 is a typo. These lists can be ordered from the Public Record Office at www.pro.gov.uk

Best regards,

Mark.

 

[Mark Chirnside]

Oh! -- as for what a Kelvin's Testing Set is, might it be something to test the compasses? Or it could be something to do with the Kelvins [sic?] sounding machine.

...No idea!

Best regards,

Mark.

 

[Dave Gittins]

Thanks to Ray Perks, who owns this device, I've become acquainted with Kelvin's Patent Testing Set #434.

I won't say too much, because it's another person's patch, but after a good deal of research, we have found that it is a tangent galvanometer. It was mostly used to measure resistance when checking insulation. By 'tangent galvanometer' we mean a galvanometer in which the current being measured is proportional to the tangent of the angle through which the needle is deflected.

Kelvin's device is very sensitive and includes a couple of rotating bar magnets that were used to cancel the effect of the earth's magnetic field on the little magnet in the galvanometer. These make the gizmo look like a primitive radio direction finder.

With the help of certain scientists, Ray is preparing a detailed description of the machine and its use. I'm thinking of asking him if I might put it on my web site, but as I say, it's his patch.

At this stage, we don't know who Henderson was. Presumably he was either a radio operator or an electrician. I favour the latter.

 

[Mark Chirnside]

Hi!

Thanks Dave for that detailed description. So it's:

An electric magnet machine?!

Best,

Mark.

 

[David G. Brown]

Dave Gittins' description of the Kelvin device brings back a memory...

Forty years ago, I recall a very similar instrument on the testboard when I was working for AT&T, the long-distance phone company. Actually, I watched someone expert in the instrument make the measurements. The device was needed to determine the distance from the telephone central office to an underground cable break. The operator had a table showing the resistance measurement of that cable when it was installed. He compared that with the measurments from the cut cable and did some mathematics which I do not recall. The result was a distance from the central office to the cut. Setting up, doing the measurements, and the calculating took most of a working day.

Cable splicers were dispatched to the spot as determined by the machine. They found a water department crew had dug up the cable while fixing a leaking pipe. That pipe crew went into a panic and buried the cut cable under 18 inches of wet concrete. The result was both a physical and a legal nightmare, which is why I recall the story. I had not thought of that test machine in at least 30 years, otherwise.

I do recall that the telephone company machine was quite old in the mid-1960s. It came in a sizeable varnished mahogany box with polished brass fittings. I believe it was manufactured by Western Electric, although I am not sure. The machine was considered extremely delicate and expensive and was only out of the storage cabinet on that one day.

Naturally, I cannot say that the device I saw was exactly the same as the Kelvin machine. However, I do recall that it had adjustable magnets and the "dial" was actually a beam of light reflected off a tiny mirror that moved with the galvanometer. I was told that the currents flowing through the galvanometer would not have been sufficient to move the mass of a conventional mechanical pointer.

-- David G. Brown

 

[sandro campisi]

if the olimpic would have crashed between 1920 and 1936 as the Titanic, whould have sank? or there was changes of structures after the sinking of the Titanic in their watersdoors.

 

[Michael H. Standart]

There were changes in the structure including the addition of what could be called a 'second skin' as well as raising some of the watertight bulkheads. This was intended to make it possible for the ship to survive the sort of damage Titanic was believed to have suffered. Whether or not it would have actually worked as designed is another question entirely. Fortunately, this was never put to the real test.