A while back someone asked about replacing the U type brake system on passenger equipment with a standard freight AB type brake system in an effort to a) prevent hernias from trying to move those U portions, and b)to save some money on the COT&S. Today I had someone else from a tourist railroad ask me the same thing, and I couldn't remember if anyone came up with a method of converting the brakes over or if such a retrofit would be feasible. <p>This particular operation operates four coaches over 5 miles of track at 10 mph, and we think that they don't need such elaborate high speed brakes for such a low speed movement. Any advice?<br>



bighookx45@aol.com

Mid-Continent has converted some passenger cars to AB brake systems, from passenger systems older than UC. A Great Northern wood coach completed a few years ago comes to mind, and perhaps one or two of the DL&W "Boonton" cars MCRM has was also converted. MCRM's Bill Raia (a Soo Line car foreman, I recall) handled these conversions, and perhaps someone associated with Mid-Continent can provide more details.<br>

It is feasible to convert older passenger car air brake systems (U-12 D-22) to a hybrid type system employing modern frieght car air brake components. The system operates similar to the old AB-1B that was used on express boxcars operating in passenger service except it does not rely on "Signal Line" air to provide for service limiting.<p>Some things to keep in mind are the application of a relay portion piloted by a dummy brake cylinder volume to assure a proper supply of air is available to fill the larger passenger car brake cylinders. A diferential type relay may be used to keep the net braking force in line with the design of the car.<p>There should also be some provision for service limiting built into the system. This is usually accomplished by incorporating an H-5 relay and a 60 lb. safety valve into the system. This prevents unusually high brake cylinder pressure from building inadvertantly during service applications but allows full brake cylinder pressure to build during emergency applications.<p>Lastly I remember that the standard AB pipe bracket needs to be modified so that the inshot bypass port is blocked.<p>Let me know if you require more info.<p>EBL<br>



ELEVIN120@aol.com

Detailed piping diagrams and parts lists for this conversion (from U-12-B to ABDW or newer freight valves) are available from New York Air Brake Division of Knorr Industries. Address Chuck Florian at that firm. This conversion was discussed at meetings of the Railroad Passenger Car Alliance several years ago.<p>The cost of the conversion cannot be justified exclusively by the cost avoided in servicing the U-12-B portions, as long as serviceable portions are available. The primary benefits are convenience and reliability.<p>Aarne H. Frobom<br>Michigan State Trust for Railway Preservation, Inc. (Project 1225)<br>P. O. Box 665<br>Owosso, MI 48867-0665<br>



froboma@mdot.state.mi.us

If you are a museum, you should keep the car as original as possible. If the brake system works fine, don't worry about it, just clean the brake valve & cylendar and the thing will work fine for years. The Niles Canyon Railway operates 3 old heavyweights on 6 miles of track at about 15 mph. The cars work fine and when one gets cranky and doesn't work properly, a quick cleaning restores performance.<br>Just a thought,<p>Johnathon Kruger<br>Steam Dept.<br>Niles Canyon Railway<br>



jkruger504@aol.com

Sorry to come on as Mr. Anonymous, but if you are not having you valves cleaned and tested by an approved shop, and you are not using a legal single car test device when applying them, you are in violation of The Power Brake Act!<br>

<br>First off, thanks to everyone who gave helpful guidance on converting U type brakes to AB. I'll be following up on that shortly. Secondly, anyone who has ever tried to change out U portions without a forklift or having more than one person would appreciate the reasoning behind wanting to change to AB. Third, an AB system will work just as well as the U brakes, are more economical for cot&s over the long run (providing you can do an inexpensive conversion), and replacemnts are readily available, making for more reliable operation.<p>Fourth, Mr. X, who at any point mentioned that anyone was not performing the required COT&S on passenger cars? What we are talking about here is a conversion from one type to another to take advantage of the benefits listed above.<p>You can give your name, we're all professionals here. (I hope).<br>



bighookx45@aol.com

If money is the issue, I found that the conversion costs associated with the change is prohibitive, especially on our cars that are also in 10-15 mph excursion service. One of the key things that I was cautioned about on cars with up to 19" body mounted cylinders is that the AB setup would not flow enough air and require cylinder bushings. <p>I don't think you need a forklift to change a UC set! We made a shelf bracket to hold the valve in position while tightening it up. I will gladly draw up a plan of the bracket if anyone needs one. A lift table would work as well if you have a flat surface and some money to buy one. In the 7 years I've done UC Cot&S I have only had one valve fail before the 15 month time anyway. I have had 3-4 AB valves fail before their 2 year time and one ABD before 2 years. Reliability?? Also if your conversion does not work as planned seemes to me you lost your advantage completely. In any case, don't throw out your old UC valves as many of us would be glad to take them off your hands!<p>In reality, most cars need the money spent on real things (rust repair, couplers, truck work, etc.) and conversion discussions are almost pointless. The 10-15 mph excursion railroad most often has better uses for their money than an AB swap. <p>As a side note, switching to AB or ABD valves does not put you in the freight brake run till failure or old 5 year Cot&S rule for passenger equipment either. Our FRA MP&E person told us that our cabooses are run as passenger cars and fall under the 2 year rule.<p>David Farlow, CMO<br>Whitewater Valley RR<br>



rfarlow@bcaconsultants.com