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| Fatal Accident at North Yorkshire Moors https://www.rypn.org/forums/viewtopic.php?f=1&t=33429 |
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| Author: | tomgears [ Sat Jun 09, 2012 12:22 am ] |
| Post subject: | Fatal Accident at North Yorkshire Moors |
A tragic accident. I rode this line last fall and thought it to be the best run tourist railroad I've ever seen. If it happened there it can happen anywhere. My heart goes out to all involved. http://www.whitbygazette.co.uk/news/loc ... -1-4623635 |
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| Author: | Matt3985 [ Sat Jun 09, 2012 12:25 am ] |
| Post subject: | Re: Fatal Accident at North Yorkshire Moors |
So sorry to hear that. Our hearts and prays goes to family of the their love one who was crushed to death. May he rest in peace :( |
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| Author: | jasonsobczynski [ Sat Jun 09, 2012 1:41 am ] |
| Post subject: | Re: Fatal Accident at North Yorkshire Moors |
It is a tragedy, no question. I read the report and it says the locomotive valve gear can change direction on it's own unless a "locking device" is used. I have only ever seen photos of johnson bars and screw reversers on british locomotives. Obviously if a johnson bar moved it would be readily noticable.... a screw reverser would have to be turned 12+times to go from full forward to reverse.... So, what other type of reversing mechanism is in the cab of locomotives across the pond? Cheers, Jason |
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| Author: | Ed Walters [ Sat Jun 09, 2012 9:33 pm ] |
| Post subject: | Re: Fatal Accident at North Yorkshire Moors |
The locomotive in question (a Southern Railway S15) has a screw reverser. From what I understand, if not locked, while in motion the screw can move enough to change the direction of the valve gear. When the regulator is opened again after stopping, the loco will start in the opposite direction. |
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| Author: | Overmod [ Sat Jun 09, 2012 11:38 pm ] |
| Post subject: | Re: Fatal Accident at North Yorkshire Moors |
I don't know if anyone here remembers the slip accident with Blue Peter a decade or so ago; the real 'proximate cause' of the slow response was that the screw reverser started to unwind and clocked the engineman in the jaw, making him (understandably!) slow to respond to the situation (which was priming/carryover at starting vaporizing in the superheater elements even with the throttle closed). Perhaps important to note that these British applications are mechanical screw reversers, not something like Franklin Precision for Valve Pilot where the screw only controls servomechanism valves, and there is internal positive location to prevent creep. I believe the Bulleid Pacifics had power reverse, but this was removed on the ones that were 'rebuilt', in favor of screw. I don't believe British Caprotti requires power assist. Don't know about Riddles standards, either, but if you go to this splendid example of how to document a historical restoration: http://fraserker.com/winson/britannia_pix/britannia/ somewhere on one of those pages will be the proof one way or the other. |
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| Author: | whodom [ Mon Jun 11, 2012 1:34 pm ] |
| Post subject: | Re: Fatal Accident at North Yorkshire Moors |
Overmod wrote: Perhaps important to note that these British applications are mechanical screw reversers, not something like Franklin Precision for Valve Pilot where the screw only controls servomechanism valves, and there is internal positive location to prevent creep. I don't know that the Franklin units were that fool-proof either. A General Foreman on the N&W who was a former NKP machinist told me he once saw a Franklin reverser ripped off the side of an NKP 2-8-4. The locomotive was traveling at ~70 MPH when the mechanical latch (which was apparently held in place by gravity) bounced out of position allowing the reverser to rapidly spin on its own to full-forward gear. This caused the mounting bolts to shear off of the reverser and he said the reverser wound up in a nearby field. I've seen it stated elsewhere that the NKP 2-8-4's were changed over to Franklin lever type reversers late in their careers because they were more often used in assignments that required switching (for which the lever-actuated unit was better-suited), but this guy seemed to believe the change was made due to similar "uncontrolled adjustment" incidents happening with the Precision reversers on other 2-8-4's. |
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