35028, "Clan Line"

Nice photos Tim

 

That's because the middle cylinder is not in line with the outside cylinders, which means that the crank pins are not exactly 120 degrees apart. As I recall the middle cylinder is about 10 degrees out, so that the exhaust of a Bulleid pacific never sounds perfectly even.

David

 

Video at Crewe:-

http://www.youtube.com/watch?v=YWv_eeq8CQk

Chris

 

You'll find more info on this thread -

http://railways.national-preservati...35028-quot-Clan-Line-quot?p=381553#post381553

Chris

 

There we have it, the engineering reason for the sound effects! Thanks for that, David.

 

Water stop at Atherstone took less than 10 minutes away at 14.38

http://www.flickr.com/photos/31339850@N06/5218907912/
http://www.flickr.com/photos/31339850@N06/5218907702/in/photostream/

graham

 

And they're always off-beat, thanks to the conjugated valve gear!

 

Obviously never heard 4771 when she was in Bill Harvey's care. As even a three cylinder beat as you'll ever hear.

 

According to Mannion's "The Southern Pacifics" the outside cylinders are inclined at 1 in 40 to the horizontal, and the inside cylinder at 1 in 7.75. My geometry is too rusty to work out the difference as degrees.

BTW, there's a new Bulleid bibliography on the SLL website:

http://www.southern-locomotives.co.uk/Class_Details/Bulleid_Bibliography.html

 

I found this on-line calculator:

http://easycalculation.com/trigonometry/triangle-angles.php

According to this 1 in 7.75 is 7.35 degrees and 1 in 40 is 1.43 degrees, so the difference in cylinder angle 5.92 degrees. However, I believe the crank is offset by this amount to give a nominally equal chuff (and torque) so the crank angles are 120 - 114 - 126 (approx) rather than 120-120-120. It's 46 years since I did Maths O Level, so I am skating on thin ice here (topical analogy)....help is welcome!

 

Pretty well spot on with the crank angles.
From drawing W11312 Arrangement of Driving Wheels and Crank Axle: -
125degrees 55minutes, 120degrees, 114degrees 5minutes.

 

Strewth mate. And all I thought you needed to know about a steam loco was that you chucked water and coal in at one end. And got steam and ash out the other end.

Plus lots of lovely noise and high speed with a Merchant Navy of course.

 

Fascinating stuff guys and answered my next question , which would have been, 'were the crank angles set to allow for this'? Thanks again. Iain

 

Was on Tring station waiting for emu to Euston and Clan Line came breezing through - totally unaware it was coming. Lucky I saw it!!

 

Has she made it out on the VSOE today?

 

yes, a few late at twickenham.
mark

 

A quick search on youtube came up with a couple of good films of today's run, worth looking for

 

Including mine: http://www.youtube.com/watch?v=5nMru9TjTNo - flogging its guts out to get away from Shalford and blitzing through Worplesdon!

It's still processing at the moment, but should be done by about 10.00 or so.

Clan Line looked and sounded brilliant, as normal. So good to see her back after her problems.

 

And here's the still I got at Worplesdon, standing in your shot I'm afraid Steve, (though I was there first.) I then saw her at Chilworth still accelerating from the Shalford stop. She slipped on the road crossing half a mile before the station and again just as she passed me on the platform but recovered fom both without any help from the 67. She looked and sounded magificent.

Don