Hello,

Here is a small video clip of the 3450 restoration in Worcester, South Africa.

https://m.youtube.com/watch?v=qVS2LC2F-EY

The big end of the main rod appears to be a spherical roller bearing....not a Timken tapered roller design in American practice. The 3450 was built by Henschel in Germany. The bearings are likely SKF.

It is also interesting to see the modern style crosshead being assembled.

Ceres wants to put it in service next month.

Regards,

Randy

Phil Girdlestone’s book on the SAR 25’s says the engines were built new with Timken rod bearings, but apparently Timken didn’t put quite the engineering effort into the application that they should have. The engines had a lot of rod bearing issues when they were put into service even though Timken had been doing roller rods for ~20 years by then and most had been trouble-free. British Timken, who had done the engineering, changed the big end bearings for a different part which seemed to cure the issue, when problems started cropping up with the side rod bearings. Timken tackled that issue too, but the SAR was losing patience. Relatively quickly, SAR went to SKF and had new bearings and at least some of the rods engineered. These rods and bearings were applied to 117 of the 140 engine fleet.

Note the SKF rods have knuckle pins on the side rods unlike Timken who avoided knuckle pins.

Hugh,

Thank you for response. It's an interesting history on the bearings. It seems logical that spherical may have advantage wth the slight angular misalignment which would occur with lateral motion devices on the drive axles. Maybe it's so slight it's not an issue with either type. The US versions held up quite well.

Unfortunately I hesitated to order Phil's book at its initial publication and now need to find it on the secondary market.

Thank you again.

Regards,

Randy

Randy,

I'm glad you found the info of interest.

I waited a little late to order my copy of the book but luckily I got it before they ran out. It really is a great book with lots of details on the design and operation of the 25's, including the condensing models. It's not surprising that the condensers had a lot of teething problems, but I was very surprised to find out about the roller rod bearing problems.

Phil also wrote an autobiography that is still available, "Here Be Dragons", detailing his work on steam across the world. It's another great book.