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| Johnson Bar vs. Power Reverse Question https://www.rypn.org/forums/viewtopic.php?f=1&t=35996 |
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| Author: | tomgears [ Thu Dec 19, 2013 5:43 pm ] |
| Post subject: | Johnson Bar vs. Power Reverse Question |
So I've always been told that the Johnson bar was dangerous and eventually outlawed. I've only been involved with on locomotive with a Johnson Bar and understand the danger was from the bar flailing around and knocking he crap out of the engineer when it was being adjusted under load. I've also always been under the impression that it was outlawed in the construction of new locomotives at some point in time. My questions are: Am I correct on the danger part? Was it indeed outlawed? Is so when and by what case/ruling? Thanks, |
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| Author: | Frisco1522 [ Thu Dec 19, 2013 6:31 pm ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
I'm thinking the ICC was involved in some way here, but someone who is better schooled in the old requirements would be better equipped to answer this. If I recall, they ruled that engines over a certain size needed to have a stoker and maybe that's where the power reverse entered the picture. |
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| Author: | Robby Peartree [ Thu Dec 19, 2013 7:04 pm ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
According to the copy of the Locomotive Inspection Law dated 1947, all steam locomotives constructed after September 1, 1937 were required to have a power reverse gear. On road locomotives built prior to Sept. 1, 1937 with more than 150,000 lbs on the drivers or switching locomotives with more than 130,000 lbs on the drivers shall have a power reverse applied during class 1 or class 2 repairs. The install shall be applied by Sept 1, 1942. For those who like burning rock the requirement for new construction took affect April 15, 1939 with the weight on driver requirements stating 160,000 for fast and heavy passenger service 175,000 for fast and heavy freight service. The retro fit requirements for stokers on non equipped locomotives are complicated and would take a bit to explain. Grabbing a Johnson bar at the wrong time could inflict injuries to the unfortunate operator. NN 40 still has a Johnson bar and I have seen some people fight with it. I would hate to see what running a bigger locomotive was like. The bar on 40 moves in a periodic pattern and the best way to move the bar was when the motion of the locomotive wanted to move the reverse gear in the direction you wanted to go. Robby Peartree |
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| Author: | Jeff A. [ Thu Dec 19, 2013 9:55 pm ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
In my own somewhat limited experience with a johnson bar, it does tend to jerk and jump a bit moving it while underway....it's a good idea to have a firm two-handed grip on it. This is at low speed and light load; Under heavy load it would have a good bit more pressure on it and probably could be dangerous. Gilbert Lathrop, in one of his Colorado narrow gauge stories, told of a D&RGW engine man who was killed by an improperly latched johnson bar. When he opened the throttle the bar slammed back catching him in the gut and apparently rupturing an intestine or something that the surgery of that era was unable to put right. J |
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| Author: | Dave [ Thu Dec 19, 2013 11:19 pm ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
I've had to fight a couple, and a few more have been not at all difficult to handle. It depends on the locomotive and standard of lubrication, among other things....... I think power reverse became a necessity when the weight of the link and associated hardware became too much for one person to handle. Anybody used to Stephenson gear knows that balancing springs don't completely balance......but the worst I've had to deal with was a piston valve conversion kit job, on which the valve decided to act like a piston itself when you tripped the latch. In the bad old days with poor lubrication and unbalanced slide valves it must have been terribly difficult. dave |
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| Author: | Kelly Anderson [ Fri Dec 20, 2013 9:30 am ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
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| Author: | filmteknik [ Fri Dec 20, 2013 11:16 am ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
Would a screw reverse obviate the need for a power reverse? Probably not too popular on a switcher with frequent need to change directions but on road power it would seem fine. The engines I've seen that have screw reverse had it controlling a regular power reverse cylinder which seems kind of pointless though I understand it allows a finer adjustment of cutoff. Steve |
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| Author: | Alexander D. Mitchell IV [ Fri Dec 20, 2013 11:18 am ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
Kelly Anderson wrote: With Johnson bars the level of lubrication of the valves and valve gear are important factors as well as the steam load on the valves, and the weather. Our #89 which is usually pretty easy to adjust when running can be very hard to move when the engine is stopped and the cylinders are loaded up with steam, similar to trying to move the steering wheel on a non-power steering equipped truck while standing still. The added resistance that sub-freezing temperatures cause within the valve gear is surprising. I recall a time when we had several hours of switching to do on a windy 10 degree day. When the diesel refused to start, #89 was fired up to do the work. The Johnson bar that could usually be horsed over with one hand in 70 degree weather took both the engineer and fireman pulling for all they were worth each time a change of direction was needed. Applying warm oil to the links would free the valve gear right up, for about a minute. Pulling an all-day switching trick in sub-zero weather with a Johnson bar equipped engine must have been dreadful. And yet, some people continue to wonder why diesels so swiftly overtook steam..... <:-/ |
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| Author: | whodom [ Fri Dec 20, 2013 11:27 am ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
filmteknik wrote: Would a screw reverse obviate the need for a power reverse? Probably not too popular on a switcher with frequent need to change directions but on road power it would seem fine. The engines I've seen that have screw reverse had it controlling a regular power reverse cylinder which seems kind of pointless though I understand it allows a finer adjustment of cutoff. Steve Yes, and wheel reverses seem to have been fairly popular overseas. I seem to recall seeing wheel reversers in drawings for some older Pennsy engines for that matter. At least some Canadian engines had an interesting variation which I saw on the Royal Hudson 2839. These had a manual screw reverser with a rotary air motor to provide speed assist. There was a small lever adjacent to the wheel to control the air motor to allow quick, major changes in cutoff (like full forward to full reverse), but minor changes to cutoff were made by manually turning the wheel. |
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| Author: | Les Beckman [ Fri Dec 20, 2013 11:30 am ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
Kelly Anderson wrote: With Johnson bars the level of lubrication of the valves and valve gear are important factors as well as the steam load on the valves, and the weather. Our #89 which is usually pretty easy to adjust when running can be very hard to move when the engine is stopped and the cylinders are loaded up with steam, similar to trying to move the steering wheel on a non-power steering equipped truck while standing still. The added resistance that sub-freezing temperatures cause within the valve gear is surprising. I recall a time when we had several hours of switching to do on a windy 10 degree day. When the diesel refused to start, #89 was fired up to do the work. The Johnson bar that could usually be horsed over with one hand in 70 degree weather took both the engineer and fireman pulling for all they were worth each time a change of direction was needed. Applying warm oil to the links would free the valve gear right up, for about a minute. Pulling an all-day switching trick in sub-zero weather with a Johnson bar equipped engine must have been dreadful. Kelly - You are right I am sure, but what is amazing to me is that this is the way day-to-day railroading was once done. In every nook and cranny of this great country! Les |
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| Author: | Alexander D. Mitchell IV [ Fri Dec 20, 2013 11:58 am ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
whodom wrote: Yes, and wheel reverses seem to have been fairly popular overseas. I seem to recall seeing wheel reversers in drawings for some older Pennsy engines for that matter. I saw a "steering wheel" reverser wheel in PRR 460 the last time I was in the RR Museum of Pa.'s restoration shop..... it's easier to see when cabside sheet metal is removed for refurbishment, after all..... |
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| Author: | Alan Walker [ Fri Dec 20, 2013 7:25 pm ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
According to accounts that I have read in the British publications, the screw (wheel) reverser was preferred as finer adjustments could be made by the driver. As previously mentioned, the Johnson bar had obvious drawbacks and I also recall reading numerous accounts of injuries to enginemen (some fatal)-mostly due to the lever striking the enginemen in the abdomen, causing internal injuries. One of the accounts was by a western engineer named Herbert Hamblen. He makes one remark in his writings of weighting coal hoppers and having great difficulty in operating the reverser due to the extreme cold and a broken spring. Based on the period in which he worked and his descriptions, I suspect that the locomotive he had had a Johnson bar. Slightly off topic, Mr. Hamblen also remarked about an occasion where a "night crawler" (locomotive with a leaky throttle valve) ran away on account of a defective spring, nearly causing a serious head on collision (alert railway employees informed the dispatcher immediately and Hamblen's train was flagged just as it was about to head out). Hamblen was later assigned to the night crawler and wrote up the defective spring until he got tired of reporting it and the mechanical department not fixing it. Eventually he made a set of chocks and used them on this locomotive. |
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| Author: | Sully [ Fri Dec 20, 2013 8:49 pm ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
I find the locomotive inspection law Robby mentioned interesting. Could someone scan & post? The NHV #17 Vulcan 0-4-0T is equipped with Johnson bar as built in 1941 I believe. |
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| Author: | dinwitty [ Fri Dec 20, 2013 10:06 pm ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
Having been around steam traction engines,, that bar has to hold the reversing pressures once latched down, move only when not throttled, if on a larger engine, small engines like steam traction engines you can move them with ease, but they still tuggle. Yep, some traction engines had the screw reverser. |
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| Author: | Russ Fischer [ Sat Dec 21, 2013 11:24 am ] |
| Post subject: | Re: Johnson Bar vs. Power Reverse Question |
49 CFR part 230 (The old version) regarding power reverse: 230.157 Reverse gear. Reverse gear, reverse levers, and quadrants shall be maintained in a safe and suitable condition for service. Reverse lever Latch shall be so arranged that it can be easily disengaged, and provided with a spring which will keep it firmly seated in quadrant. Proper counterbalance shall be provided for the valve gear. (a) All steam locomotives built on or after September 1, 1937, shall be equipped with a suitable type of power-operated reverse gear. (b) ALL steam locomotives used in road service built prior to September 1, 1937, which weigh(2) on driving wheels 150,000 pounds or more, and all steam locomotives used in switching service, built prior to September 1, 1937, which weigh on driving wheels 130,000 pounds or more, which are equipped with manually operated reverse gear, shall have a suitable type of power-operated reverse gear substituted therefor the first time that said locomotives are given repairs defined by the United State Railroad Administration as class 1(3) or 2,(4) and all such steam locomotives shall be so equipped before September 1, 1942. (c) Each steam locomotive used in road service, built on or after March 1, 1946, that has an air operated power reverse gear shall be equipped with a connection whereby such gear may be operated by steam or by an auxiliary supply of air in case of failure of the main reservoir air pressure. Each steam locomotive used In road service, built on or before March 1, 1946, that has an air operated power reverse gear shall be so equipped the first time said locomotive receives a class 3(5) or heavier repairs after June 1, 1946. if an independent air reservoir is used as the source of auxiliary supply for the reverse gear, it shall be provided with means to automatically prevent loss of pressure In event of failure of the main reservoir air pressure. (d) When steam connections to air operated power reverse gear are used, the operating valve handle shall be conveniently located in the cab of the locomotive and so arranged and maintained that in case of air failure steam may be quickly used to operate the reverse gear. The operating rod or lever shall be plainly marked and equipped with a handle or wheel of a distinctive design. 230.158 Modifications of rules. Upon application to the Director, Bureau of Railroad Safety, modification of the rules in this subpart not inconsistent with their purpose, may be made for roads operating less than five locomotives, if an investigation shows that conditions warrant it. Footnotes (2)Weight on driving wheels means the weight of a locomotive in working order that is supported by the coupled driving wheels when it rests on a straight and level track, as defined in the Locomotive Cyclopedia. (3)New boiler or new back end. Flues new or reset. Tires turned or new. General repairs to machinery and tender. (4)New firebox, or one or more shell courses, or roof sheet. Flues new or reset. Tires turned or new. General repairs to machinery and tender. (5)Flues new or reset. (Superheater flues may be excepted.) Necessary repairs to firebox and boiler. Tires turned or new. General repairs to machinery and tender. Note the loophole in part 230.158. This is where some of the exceptions likely originated. Russ |
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