Cross Heads - 2E EK- What Drawings?

[Dosedmonkey]

Hello,

I'm a heavily medium speed experienced person, like a lot of British guys nowardays.

And we have been given hand outs on Cross Heads today, and there is loads of Cross Heads in there, even Doxfords. Is there a generic drawing, or specific ones I should be learning to draw?

Many thanks.

[Chiefy]

Normally it's sketch and describe, so make sure your words match your picture, watch for phrases like .....explain how you would carry out a survey, how are slipper clearances adjusted or checked. But other than doxfords opposed piston cross head they are very much of a muchness.

[Clanky]

I would make sure that you can draw the palm type with the piston rod bolted to the top of the crosshead and the bolted through type and understand the differences between the two in terms of stiffness.

Forget about the Doxford stuff, it simply won't be asked about in the EK papers.

You will need to know what to look for in terms of bearing inspection, slipper clearances, etc.

I can't remember the term for the cracking / breakup of the bottom half of the bearing, something like tortoise shelling?

IIRC, I had to describe the procedure for opening the cross-head on a Sulzer without removing the piston for my seconds motor paper.


As always, look through the past papers and see what has come up in the last 10 years or so.

[Chiefy]

Yes forgot about bolt on and bolt through cross heads, however both Wartsila (sulzer) and MAN (B&W) have moved over to bolt on type and have been there for a good while.....since the RTA for Wartsila and forever (as far as I cane see) for MAN

Also look at how the piston cooling is effected, elbows, stand pipes etc, oh and lubrication of cross head, Wartsila use stand alone electric cross head pumps MAN dont....

[Dosedmonkey]

Thanks for help guys.