Steam Locomotive Booster Engines

Well, lets give this a try:

1) There is a Pre-throttle valve that is opened when the booster system is first "engaged".

2) Yes, the booster can be idled, via the pre-throttle.

3) The boost is generally "cut in" when stopped, in order to start a heavy train. However, we have encountered a number of cases with 4449, when the speed slowed to a "danger of stalling" point, at which time the booster was started & in gauged in order to maintain speed and proven a stall.

4) Yes, I believe that 4449 originally had "booster sand".

5) On 4449, the booster cylinder cocks are opened, which has recovered the slip in the few instances that a boozer slip occurred.

6) Yes, the booster becomes disengaged as soon as the Alco power reverse is "hooked up" from full gear forward. At which point the compressed air operated pinion gear is pulled back out of the bull gear on the number one axle of the trailing truck.

7) I don't know about 35MPH, but the booster on 4449 is good for something above 20MPH, IF engaged at starting. As I recall, our booster should not be engaged above 15MPH while moving (just from memory).

8) The booster exhaust on 4449 is piped into the exhaust stand, in the front end.

9) No, I never noticed that effect. What with the speed down below 12 to 10MPH, the piston thrusts tend to swing the cab from side to side, even with the booster on and the throttle wide open.

10) The most memorable instance was on the Freedom Train. We had been on display at Danville, Va on the Southern Railway. Our next display city was Charlotte, NC, and as usual the Freedom Train generally moved at night. Long before our midnight departure, after reassembling of the whole train, a Southern Manager came by and apologized that they, the Southern, would NOT be able to provide a diesel helper to assist us out of the river valley, and up the long grade southbound out of Danville. Chief Mechanical Officer & Engineer of AFT 4449, Doyle McCormack, requested that the full Freedom Train be assembled on the down grade north of town. Thus we would have a running start for the southbound ascending grade. The Southern Manager agreed, and that is what they did.

After the train was assembled north of town, we backed out of our display location, and proceeded north and up hill to the complete Freedom Train. The air test was complete, and   we received permission to depart southbound. Danville, Va was a main line stop and refueling location for the famous Southern Crescent passenger train, so at each end of the double track passenger station were diesel locomotive fueling facilities.

Just as we are ready to depart, it started to rain, and I mean RAIN! The old saying about the cow and a flat rock comes to mind. Anyway, down the grade we come, cross the river, into the passenger station, and,,,,,,,,,,,4449 slipped big time! McCormack recovered quickly, continuing through the station and across a street crossing and,,,,,,,she slipped again, he recovered,,,,,and she slipped again. The rain was so heavy that we really couldn't see much ahead, and it was quickly obvious that 4449 was going to have a difficult time with the train on this long, .75% to 1% ascending grade (we didn't REALLY know how steep the grade actually was).

McCormack quickly warmed up the booster, and when our speed was about 12MPH, he engaged the booster. Man that thing uses a LOT of steam and water! Our speed finally settled at about 9 or 10MPH (the SP speedometer only goes to 10 on the face), and she finally just dug in with the whole train on the grade. We must have spent close to an hour on that darned grade, with the cab swinging left and right with each piston thrust. After about 15 minutes, we were beginning to get a strong smell of burnt asphalt coming up through the cab floor. By then the booster was so hot that the old original bunked C fuel coating the top portion of the booster, from the regular service steam days, was becoming soft and smoking. What a smell! 

We ascended the entire grade at full throttle, with the booster engaged, in a DRIVING rain storm, at a steady 9 to 10 MPH, and she didn't slip any more.

The funniest part of the whole trip, was pulling into the display area in some state park. They wanted the train in backwards, but with 4449 on the rear end. Upon arrival, the southern had two diesels lined up to turn the whole train, and then push the rear end up against the 4449 and we would then pull the whole train into this park. Of course it's still raining like the cow and the flat rock!

Anyway, the move is finally done, we get a Pilot Engineer, and away we go down this branch line at about 20MPH. Gradually, we are going slower and slower, even as McCormack is INCREASING the throttle. Finally we are down to about 10MPH, throttle wide open, and things are NOT looking good,,,,so McCormack puts the booster on again. We still continue to slow down and finally the piston thrusts are so far apart that we don't know when the next exhaust will come! Finally we stall,,,,,,at FULL THROTTLE and the booster engaged! HOW CAN THIS BE????

Finally the Pilot Engineer says, "Well, not to bad guys. A diesel is only rated for some 1300 tons on this hill." Since the Freedom Train was well over 2400 tons, that idiot KNEW we couldn't make the hill, but just wanted to see how far we could get! McCormack quickly shut everything down (I thought McCormack was about to kill the Pilot Engineer at that point), I got the fire calmed down, and the two diesels pushed us into the park at about sunrise. In spite of her 80 inch drivers, 4449 never slipped at all, at full throttle, in a driving rain storm. Pretty darned impressive, I'd say!

Hot Water,

Fantastic information and great stories.  By any chance were you firing on the famous high speed 4449 move from Atlanta, GA to Alexandria, VA in August '76?

--Reed

that's a heck of a story HW, but please... you've got to tell about what a cow and a flat rock is!

No, I did not make that movement. However, I was Fireman on the "much higher speed" move on the Illinois Central, in the spring of 1977 (Amtrak Transcontinental Steam Excursion, from Birmingham, AL back to Portland, OR). South of Jackson, MS, enroute to New Orleans, we reached a shade under 90MPH. One of the "officials" in the cab from the IC, made a crack to McCormack about " How fast will this old thing go?",,,,,DEFINITELY THE WRONG THING TO SAY! We scared the crap out of them, because the track was so rough (still jointed rail), and obviously was no longer good for 117MPH as "The Main Line of Mid-America". I've never seen so much dust and stuff fly out of the back head as on THAT trip.

Hot Water those were very interesting stories. Make me wish I would have paid more attention to my Dads and Grandpas stories.

I agree, great stories HW, more importantly what great experiences.

Fabulous accounts HotWater and very interesting information about the boosters. There are so few people who have first-hand experience with operating a heavy train with steam power. So I gather that boosters were primarily intended for short-term use for train starting and to engage a booster continuously on a grade was pushing their capability.

I have the impression that many locomotives that were originally built with boosters did not have the boosters retained after a major loco rebuild. I gather that they may have been a high-maintainence item and possibly subject to major damage if, for example, they were used excessively?

1) For passenger service, yes the booster was pretty much only used for starting heavy passenger consists out of a station which may also have had a slight ascending grade out of the depot. Good examples were the NYC J class Hudsons.

2) Concerning booster use on grades, I don't think prolonged usage was ever an issue. 

3) Boosters were NOT necessarily removed after a "major loco rebuild", since a "major loco rebuild" tended to happen every 5 or 10 years. Removal of the boosters was pretty much based on reducing maintenance costs. Some railroads like NYC removed the booster from the Hudsons pretty late in their working lives, but the SP retained their boosters right to the very end of steam.

Hot Water,

That is just a superb account of typical operation of a booster engine, and it is greatly appreciated. I enjoyed the technical info, but it is GREAT reading as well. A booster added about 14,000 lb. of tractive effort, and I am sure in some cases it was THE difference in completing the run.

As for your experience, well, you know what they say about "street cred"....!

Thanks 5432. I'm glad that I was able to answer all your questions. Yes, I certainly have been blessed with a great career and many, many fantastic experiences with both steam AND diesel locomotives. Most times I have VERY pleasant remembrances & dreams of past events, in spite of those 3 or 4 that occasionally still give me nightmares.

"those 3 or 4 that occasionally still give me nightmares."

oh, too good to pass up.  

care to relate one of them???

Perhaps the tender seperation during the Worlds Fair trip to New Orleans?

Perhaps I could ask some other questions about steam locomotive operation - specifically, about the use of throttle and cutoff to power a heavy train.

On rare occasions I've operated 7.5" gauge live steam, and I've "operated" steam trains on computer with MS Train Simulator.

This is what I understand so far. Basically, you start out with long cutoff (if that's the correct terminology) and ease out on the throttle to start a train. Cylinder cocks open for the first few revolutions to blow out condensation. As you build speed you shorten the cutoff to conserve steam. I think of cutoff as a variable speed transmission, I understand how that works. What I don't understand is the finer points of balancing throttle and cutoff with the train up to speed.

In train simulator, when the train is up to speed, you can just leave the throttle around 80% or 100% and gradually shorten the cutoff to control speed. In actual practice I guess that may give "choppy" power impulses at slower speeds; I think I noticed that on the live steam. So I suspect there is some technique to not go too short on the cutoff and instead cut back on throttle, depending on the speed. I wondered if there were some general guidelines on that? Of course there must be a lot of differences between different types of locos.

cab of 4-6-2 #3820 at Thirlmere Railway Museum NSW

OK Forrest,

Following-up in the high speed running on the IC, back in 1977, was what actually led us to that, "How fast will this old thing go?" issue.

We were told that our departure, southbound out of Jackson, MS would have to be on the NORTHBOUND main track, since there had been a minor derailment of a bulkhead flat car in a lumber yard siding, which COULD be fowling the SOUTHBOUND main track, some 30 or so miles south of Jackson.We would be speed restricted to a maximum of 60MPH, since we would be running "against traffic", until we could cross back over to the SOUTHBOUND main track, south of the MOW crew that was re-railing the offending car.

Now, McCormack was already in a bad mood that morning, because the fuel truck driver was NOT smarter than his rig, and had squirted McCormack with some nice warm, black #5 power plant fuel oil! So,,,,,away we go southbound on the "wrong main", with two IC officials (Road-foreman & Trainmaster), plus a Pilot Engineer in the cab. At 60MPH we commented that the track was "sort of rough", but one of the officers indicated that it was due to our running "against the grain". OK, I guess we'll see about THAT, later.

We finally approach the derailment location and slow in order to acknowledge the MOW people, with lots of bell & whistle and waving. All of the "action" is on the Engineer's side.

OK, back to 60MPH again. It's hard to remember anymore how far we proceeded south, but I do remember McCormack's voice asking, "Where is this cross-over, to go back to the South Bound main?". Within seconds, he places the brake valve in emergency, and shuts off the throttle! I look forward and see a little red flag stuck in the hand throw switch stand and,,,,,,,,,,the switch is OPEN. It is the 15MPH crossover we have been looking for, and all three of the IC guys in the cab TOTALLY FORGOT ABOUT IT! Holy S&^T, we are all going to die right here.

My mind went into "slow motion", and it seemed as though it took 30 minutes, even though we were in emergency, to reach that darned crossover. When we entered the switch, we slammed to the right, then back to the left as we completed the crossover and entered the southbound main. Our entry speed had gotten down to 45MPH, and we finally stopped with the engine, tender crew car and the first Amtak "first class" passenger car through the crossover. I looked down, and the ballast was still "down" , then looked up, and the sky was still "up", and realized that we had not turned over. We all got off and inspected everything, and discovered that EVERYTHING was still on the rails, no one had been injured in the crew car, nor in any of the passenger cars.

At that point, we were beginning to calm down, when one of the IC officials said, "Well,,,,I guess we all forgot about THAT." I really thought McCormack was going to slug him! I yelled, "Mac,,,,,WAIT!!", and he looked at me, didn't say a word and got back up in the cab. I got the fire going again, and we then pulled the rest of the train SLOWLY though the crossover. No more 60MPH max speed limit, so McCormack took us up to 70 or 75MPH, but the southbound main was NOT actually "less rough" as the northbound track had been. So much for "running against the grain" bs!

quote:

and all three of the IC guys in the cab TOTALLY FORGOT ABOUT IT! Holy S&^T, we are all going to die right here.

Sounds to me like more than three people forgot about that 15 mph crossover!

So this was the crossover incident - I had never heard the details of it. I do remember that there were rumors later of serious damage to the 4449 (frame?) which were denied or repaired, I guess.

I can't help but wonder why there weren't written train orders or track signals that would have avoided a surprise encounter with a crossover at speed. Apparently the tracks weren't signalled for bi-directional runnning. The main line of mid-America.

More great stories Hot Water.  Enough for a book?

Having had the chance to fire both 844 and 4449, do you have a favorite?  How similar or different are the two?  On paper they both have 300 psi boiler pressure and 80 inch drivers but I'm sure they have their differences.

--Reed

predicting his fav is 4449

Naturally between the two 4-8-4s, my favorite would have to be 4449. However, probably not for the reason/reasons you think. Sure I've spent over 37 years with McCormack and "Big Wheels", but the 4449 is a bit more difficult to fire and thus more challenging. The 844, especially with her all new welded firebox, is so easy to fire that it really isn't that much of a challenge.

Now, to be honest, my real favorite is UP 3985! She has always been a real handful and she keeps you on your A game, ALL THE TIME.

Now just why do you ASSUME that? Our 4449 cab crew had NEVER been over the IC, and had no idea what mile post that crossover was supposed to be at, since they never told us. Besides, between the Road Foreman, the Trainmaster, and the Pilot Engineer, at least ONE of them could have/should have kept us ALL informed!

Absolutely NO DAMAGE was done to the frame or running gear.

What DID happen, later in the trip, one of the bottom row boiler tubes cracked at the rear tube sheet. She proceeded to dump her boiler water, obviously putting the fire out, and we got towed the last 30 or so miles into New Orleans Union Passenger Depot. We had a 2 day layover there, and plugged that tube.

Great info HotWater, we all appreciate your firsthand accounts.

All great engines, the pride of American steam which I have been occasionally privileged to witness in person.

But the smoke seems kinda heavy.

Hot Water,

Did you ever fire or ride on the SP2472?  I'm not an engineer or anything, but I helped film a documentary on the 2472  I've was able to ride in the cab a few times and many of the trains it pulled.  Also did you know an engineer named Errol Ohman?  He engineered the 2472 many times and was the engineer on the 2467 when it was still in service.  He just recently passed away.  Matt

In order to try and make the relationship of throttle and cutoff positions more clear, lts start with some basic information.

1) The steam engine is essentially a "heat machine", i.e. it uses the power of heat expansion to produce the cylinder horsepower.

2) The heat is conveyed from the fire in the firebox, to the water, which is boiled in the boiler, to the steam, which is then superheated (and dried) by way of the superheater units, and then to the valves for final distribution to the cylinders. Thus, the "transmitter" of the heat energy is via STEAM.

3) The higher the boiler pressure the HOTTER the steam temperature, which is THEN superheated up to the working temperature (550 to 750 degrees F on the big superpower locomotives).

4) The pressure of the steam is NOT was does "the work", it is the heat of expansion. This becomes VERY important when PROPERLY adjusting the valve cutoff! 

5) When starting, the power reverse gear is placed in FULL FORWARD, thus providing maximum available steam flow/volume. As the throttle is eased open, the hot steam begins it flow through the valves and into the cylinders to do its "work". As the locomotive accelerates, the stroke of the valves need to be shortened in order to reduce the volume flow of the steam, which then allows the steam to continue to be superheated in the superheater units. The longer the steam takes to flow through the superheater units, the hotter the steam will be entering the valves. Thus, by shortening the stroke of the valves, i.e. "hooking her up", the steam VOLUME demand reduces, but the TEMPERATURE increases!

6) Now lets say you are up to cruising speed and you do NOT want to accelerate any more. At this point the throttle must be reduced (exactly HOW MUCH, comes with experience), however the power reverse gear must be re-adjusted back "down" in order to allow the cylinders to "breath". This adjustment slightly lengthens the stroke of the valves and thus keeps a steady flow of steam through the superheaters, which maintains maximum steam temperature and corresponding HP for the cylinders. By reducing the throttle, the steam volume was correspondingly reduced, so the valve stroke MUST be lengthened in order to maintain the PROPER steam flow through the system and into the cylinders. The Engineer's experience, and KNOWLEDGE, about all this is EXTREMELY important. Thus the Engineer can tell by the sound of the exhaust at the stack, that he has the valve gear set correctly, when that "crack" or "pop" returns to the stack after reducing the throttle and then CORRECTLY lengthening the valve stroke.

Hope this explanation helps a bit.

Sorry Matt. I never spent any time on either of the SP Pacifics, nor met Mr. Ohman.

I think the tender separation event on the 4449 happened near Sanderson TX, as the World's Fair Daylight was going home.  The crew got some hoses from the fire department.

BTW, does that mean the 4449 crew obtains water hoses between engine and tender from the same sources as the fire departments?

1) The tender separation incident was only about 15 miles west of Dell Rio, TX.

2) The Dell Rio Fire Dept. were in the process of restoring an "old Fire Engine" so we took up a collection among our crew and "donated" $500 to their restoration fund. They gave is the big hose that would normally been carried on the front of the pumper, for connection to the large fitting on a fire hydrant. We used our powered hack saw and cut the hose in half. That hose stayed on 4449 for quite a few years after that.

3) I would imagine that such hoses have MANY uses.

fascinating stuff, Hot Water, thanks.  

Great information HW, thanks for sharing it. 

Thank you so much!! My wife and I saw the T1 Freedom Train running West Bound thru Phillipsburg,N.J. What a beautiful sight that I fondly remember to this day. How can we persuade Mr. Melvin and you to become guest speakers at a convention or some other gathering to discuss steam loco operation? This is history and fabulous story telling! Thank you again!!

I don't see any problem with that, speaking just for myself, and not Rich. I would not expect to be paid, but reimbursement for travel expense to, during, and return home from your "event" would be in order (depending how far away it was).

whoa!  throw al krug in there with Hot Water and Rich and that would be some lineup.  you could sign me up right now!