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Jimc's Recent Activity

  1. Jimc liked Evening Star's post in the thread Boilers with flue tubes but no superheater elements..

    Hi, There's no modification to airflow on 1450 or 1466 to my knowledge. Reg.

    Feb 21, 2024 at 2:58 PM
  2. Jimc replied to the thread Boilers with flue tubes but no superheater elements..

    I've had confirmation that there's no especial restriction in the corner tubes. I've had sight of 1902 and 1932 drawings of tube layouts of 2301 (eg 1854, 57xx pannier tank boilers) . Can't really answer James' question about tube layouts from...

    Feb 21, 2024 at 12:12 PM
  3. Jimc replied to the thread Steam speed records including City of Truro and Mallard.

    Nothing is precisely accurate, but GPS traces are very good indeed provided that you analyse a log rather than simply take instantaneous readouts as gospel. I agree that the instantaneous speed figures are of limited value.

    Feb 21, 2024 at 9:05 AM
  4. Jimc replied to the thread Boilers with flue tubes but no superheater elements..

    If I have the right figures from lner.info then the Ivatt Atlantic had 32 flue tubes and with superheater elements removed would have almost 40% of cross sectional area in the flue tubes, as opposed to 2.5% in the GWR boiler. It doesn't seem a...

    Feb 21, 2024 at 8:39 AM
  5. Jimc replied to the thread Boilers with flue tubes but no superheater elements..

    Even more surprisingly perhaps RCTS suggests that when superheating was removed from pre group pannier tanks like the 1854s around 1930 the elements were simply removed leaving the flue tubes unaltered and the boilers still capable of being...

    Feb 20, 2024 at 2:17 PM
  6. Jimc replied to the thread Boilers with flue tubes but no superheater elements..

    This page has a good few photos of the boiler of 6412 (a Standard 21) under repair, and there are various views of the tube layout. I've struggled to find good images of the firebox end. https://www.southdevonrailwayassociation.org/6412.html

    Feb 20, 2024 at 1:22 PM
  7. Jimc attached a file to the thread Boilers with flue tubes but no superheater elements..

    > Do you know what the tube bank looked like on similar boilers without the flues? Not in detail, and detail counts! Here's the RCTS list of unsuperheated P class (large pannier tank) boilers with belpaire fireboxes. As you can see there are...

    upload_2024-2-20_12-39-54.png Feb 20, 2024 at 12:53 PM
  8. Jimc replied to the thread Boilers with flue tubes but no superheater elements..

    You'd need to consult someone who works on them, but I haven't heard of such. If my sums are right its only 2.5% of the total cross sectional area. In my ignorance I find it hard to believe the air flow is very even across the entire tube plate.,...

    Feb 20, 2024 at 12:22 PM
  9. Jimc replied to the thread Boilers with flue tubes but no superheater elements..

    I would imagine it was pragmatic, based on experience, rather than theory. Plenty of P class boilers on pannier tanks had been superheated before 1925, with a single row of flue tubes, and by this date the superheater elements were being removed....

    Feb 20, 2024 at 8:15 AM
  10. Jimc posted a new thread.

    Boilers with flue tubes but no superheater elements.

    From 1925 the GWR fitted a pair of 5 1/8 diameter flue tubes in the upper corners of untapered boilers that had belpaire fireboxes, pressure 165psi and above and no superheater. This is reckoned to have reduced cracking in the corners of the...

    Forum: Steam Traction

    Feb 20, 2024 at 5:35 AM