Gunn gets a taste of his own medicine

[battalion51]

As we all know David Gunn made some radical changes when he came into office last year. One of these moves was to reduce the number of engines used, this meant many trains like the Silver Meteor, Silver Star, and Palmetto were to run with one engine when no Express was being carried. Well, David Gunn came into Jacksonville yesterday to accpet a Presidential award on behalf of Amtrak, he arrived in town on P091. After accepting the award Mr. Gunn boarded P098 to return to Washington. Well just outside of Rocky Mount last night 98 suffered a massive engine failure. They were delayed over 6 hours, had the crew outlaw, and didn't arrive into Washington until 1:25 this afternoon (for those who don't know 98 is supposed to arrive at 5:45 in the A.M.). As of the last report at Philadelphia at 4:23 they were 7 hours and 43 minutes late. Now Mr. Gunn knows why running two engines makes sense, considering he sat in a sleeper where temperatures were in the mid 40s. For the record, Hialeah did a very nice job replacing the carpet cushions, and all that stuff in Mr Gunn's room.

 

[Bill Haithcoat]

Well, that is an interesting thing to happen. I was against reducing the number of locomotives anyway.....maybe he will have second thoughts on this. This was one of the few of his changes I did not like.

 

[Viewliner]

There's one question I like to think of with this:

What would Claytor Do? I could only picture his reaction :lol:

 

[battalion51]

Claytor probably wouldn't have been on the train to begin with. But if he was on board he probably would have gotten off and walked to the nearest airport. :lol:

 

[P40Power]

I agree totally, I think long distance trains (maybe even some medium distance trains) should be have at least 2 locomotives manditory!

If fuel cost savings is the goal, could a second locomotive be towed dead along and fired if necessary? Or have one dead until the first one runs out of fuel and then use the power and fuel of the second?!

Seems to me though towing a unit would take up extra fuel and horsepower though. Better off to spend the money for the reliability and extra horsepower of 2 units (though on occasion both locos can go down, then there is problems!!

 

[battalion51]

I'm going to let you all in on a little cas study an Engineer buddy of mine did last year when we were carrying two engines and comparing it with one engine hauling trains of the same length. Between JAX and MIA on a round trip they saved 400 gallons of fuel by running both units vs. running just one unit. Of course there are many visible benefits to this, reliability, fuel savings, faster load times, and a much quieter lead cab if the HEP load is placed on the trailer. So, why Amtrak continues to waste 400 gallons of juice per JAX-MIA round trip is beyond me.

 

[AlanB]

I'm not saying that your buddy is wrong, however that doesn't make sense. All other things being equal, one can't move an extra 266,000 pounds with less fuel. The savings in fuel might not be too much, but one can't move more weight with less fuel.

There must be something wrong with his anaylsis or some other mitigating factors at work here. Perhaps more idle time, different weather conditions, or something.

Besides David Gunn is enough of an engineer that he wouldn't have made such a decision if it was going to cost Amtrak more in fuel. Wear and tear on the engines aside, this was a cost savings measure. Something of this magnatude would not have been decided on a whim.

 

[Amfleet]

I have to disagree with you guys. If one locomotive can handle a train on its own perfectly fine, then there is no need for second unit. Even if it is for back up, it's just a waste and will drive up maintenance costs on that particular unit when it isn't even needed. You have to think just more than fuel costs. For when there is a rare occasion when a locomotive will break down en-route and there is no back up, everyone will have to deal with the delay. Still, Amtrak probably looses more money just by running an extra unit for backup all year long than it does on passenger refunds for that one trip.

I like to think of it this way. If your car breaks down on that very rare occasion, you don't just tow a second one for back-up. That's just a waste of some $15,000 when you can just call for roadside assisatance and pay no where near that amount. Yes, it does put a bump in your day, but valuable money could be used elsewhere. IMHO The same reasoning is behind Gunn's move, just thinking economically.

 

[battalion51]

I am going to have to disagree with you Amfleet. One engine isn't enough to haul those trains. If you go pull the tapes on any Silver Service train with one engine, you'll notice that coming from a dead stop to MSA the Engineer has his throttle in the 8th notch the whole time. Now you might be saying, "Well every Engineer does that." It's the length of time that it takes to get up to speed that's the killer. From a dead stop the Engine is in the 8th notch for 2-3 minutes under ideal conditions with no grade, no relative wind, rain, snow, etc. Add in mother nature's elements and it could be a period more like 4-5 minutes. Now take the average commuter operation, to get up to speed it takes approximately 1 minute from a dead stop, which is close to what it should be. Now we can sit here and argue about fuel all we want, but the simple fact is that once you get up to speed you can cut out (idle) one of your engines and cruise with the remaining engine. This is done in many cases like on the Empire Builder, Cal Zephyr, and SW Chief. All the Engineers pour on the Horsepower to get up to speed and then cut out the trailing units that they can. So, IMHO two units are necessary for any train exceeding 10 cars in length. Now, if you know the generally accepted policy in running a passenger railroad, you know that above 8 cars, there should be a trailing unit. So 2 engines are definitely needed on this train.

 

[AlanB]

Well again there is something to be said about the redundency of an extra engine, should one fail. I can't really speak to whether the cost of wear and tear on that extra engine outweighs safety and passenger comfort should a single engine train have an engine failure.

I also understand that the amount of time to reach track speed will be longer with one engine than it would be with two. However I'm not sure that taking 3 to 4 minutes more to reach MSA on a LD train is significant. Lets take a Silver Service train for example the Silver Meteor. From DC to Miami it covers 1,164 miles. During that time the Meteor makes 26 stops.

So taking your numbers if it takes 3 minutes longer to reach track speed with one engine, than two, that would only add a little more than one hour to a train that already takes 23 plus hours to make it's run. That's not to significant in the overall scheme of things. Although an hour is indeed an hour and anything that Amtrak can do to get it's times down would be helpful.

However since in most cases Amtrak did not add more time to it's runs when the single engine consist came into play, they can't be loosing too much time. Especially since every so often Amtrak does actually manage to arrive on time. So it would appear that either my math is wrong or the amount of time to reach MSA is not that different with one vs. two engines.

Next comparing a commuter operation to Amtrak is a futile exercise. That's like comparing apples to oranges, one has nothing to do with the other. Again returning to the Meteor, there is an average of 43 miles between stops on the Meteor's run. The average number of miles between stops on a commuter RR is around 2 or 3. So reaching MSA as quickly as possible in a commuter op is far more important, than it is for Amtrak.

Of course in most cases on a commuter op, unless there is at least 5 miles between two stops the train can't reach MSA anyhow. There is simply no way to accelerate to 70 MPH and still make your next stop, if your next stop is only 2 miles away.

 

[PennsyFan]

I'm sorry to say it, Alan, but your math is wrong. It takes 3 minutes longer to reach track speed, but the train is moving in the time spent speeding up. It's not as if the train is spending three minutes sitting, and then suddenly speeds up at the normal rate. Also, Batallion 51 said it took 3 minutes total to reach track speed, rather than 3 minutes more.

The math would look a lot more complicated than anything anyone has suggested. You'd have to find the rate of acceleration and calculate out how fast the train is going at each phase of acceleration. If anyone here feels like taking a shot at it, go for it.

Whatever the answer turns out to be, however, it is still clear that the second engine wouldn't make that much of a difference. It would certainly be nowhere near an hour.

 

[AlanB]

I'm sorry to say it, Alan, but your math is wrong. It takes 3 minutes longer to reach track speed, but the train is moving in the time spent speeding up. It's not as if the train is spending three minutes sitting, and then suddenly speeds up at the normal rate. Also, Batallion 51 said it took 3 minutes total to reach track speed, rather than 3 minutes more.
The math would look a lot more complicated than anything anyone has suggested. You'd have to find the rate of acceleration and calculate out how fast the train is going at each phase of acceleration. If anyone here feels like taking a shot at it, go for it.

Whatever the answer turns out to be, however, it is still clear that the second engine wouldn't make that much of a difference. It would certainly be nowhere near an hour.

PennsyFan,

I kinda figured that my math was wrong, but I was trying to keep things somewhat simple too. Plus I didn't want to get to deep into physics and heavy math. Especially with my fourth glass of wine for the night at my side.

However as I mentioned changing from two engines to one has not altered the times on the Northbound Meteor between Miami and DC, which is the train I was using in my example. So it would appear that the amount of time needed to reach track speed with one enginer vs. two is not an issue.

 

[amtrakmichigan]

maybe this is a good example of why Amtrak should have kept some old f-40's around. They would have made a good trailing unit, then fired up when needed. I have to say that too much power is not always a bad thing. It is possible that a single locomotive that is overworked, especially with acceleration could take about the same amount of fuel as 2 locomotives sharing the work. Fuel cost isn't the only thing to consider, if your burning up locomotives because they are stained constantly, then I dont see where the cost savings would be shown over using 2 units. The same works with cars, The Ford Mustang is a good example of this. The V-6 with 190 HP Mustang only gets about 4 MPG more then it's GT counterpart with a 260 HP engine. The V-8 doesn't have to work as hard as the 6 to do the same job. Of corse getting up to track speed is the hardest work a locomotive encounters, once there it's easy street the rest of the way (except for big grades)

 

[PRR 60]

I'm sorry to say it, Alan, but your math is wrong.  It takes 3 minutes longer to reach track speed, but the train is moving in the time spent speeding up.  It's not as if the train is spending three minutes sitting, and then suddenly speeds up at the normal rate.  Also, Batallion 51 said it took 3 minutes total to reach track speed, rather than 3 minutes more.  
The math would look a lot more complicated than anything anyone has suggested.  You'd have to find the rate of acceleration and calculate out how fast the train is going at each phase of acceleration.  If anyone here feels like taking a shot at it, go for it.  

Whatever the answer turns out to be, however, it is still clear that the second engine wouldn't make that much of a difference.  It would certainly be nowhere near an hour.

You asked for it!

Given: The train with one P42 takes 3 minutes to get to 80mph. The train with two P42’s takes 2 minutes to get to 80 mph.

Find: The time added to the trip for each 0 to 80 mph acceleration by the one unit train.

Assumption: Acceleration is constant from 0 to 80 mph.

OK, here we go!

Lets take a train with one P42 accelerating from rest to 80mph in 3 minutes. 80mph is 117 feet per second. Moving from rest to 117fps in 180sec. is an acceleration of 0.65 feet per second per second (fps2). Good so far? OK!

Now, the distance covered by an accelerating vehicle is equal to the acceleration (A) times one half the elapsed time squared or:

S=0.5 x A x time x time (take my word for it)

Plugging in our numbers, we get:

S=0.5 x 0.65 x 180 x 180 = 10,560 feet. <== that is EXACTLY 2 miles! Amazing!

So, the train with one P42 takes 10,560 feet to go from rest to 80 mph. It covers that distance in 3 minutes.

Now, lets say a train with two P42’s can accelerate to track speed, 80mph, in 2 minutes (one minute faster than the one unit train). That’s an acceleration of 0.98 fps2. The distance covered to get to track speed is:

S=0.5 x 0.98 x 120 x 120 = 7,040 feet.

So, the train with two P42’s is at 80 mph after just 7,040 feet. To cover the same distance the train with one P42 used to get to track speed, this train will move an additional 3520 feet (10,560 – 7,040) at 80 mph (117 fps). The time needed to move 3,520 feet at 117 fps is:

3,520/117 = 30 sec

So, to cover 10,560 feet starting from rest, the train with two P42’s takes 120 seconds for acceleration to track speed in 7,040 feet, and another 30 seconds at track speed to cover the remaining 3.520 feet, or a total of 2.5 minutes.

Ah ha! The train with one P42 takes three minutes (180 seconds) and 10,560 feet to get to 80 mph. The train with two P42’s covers that same 10,560 feet in 2.5 minutes. Therefore, dropping one P42 adds one half minute to the running time for every start from rest to 80 mph.

Isn’t physics fun!

 

[AlanB]

Isn’t physics fun!

PRR60,

Yes it is.

And thanks for the math.

Based upon your numbers that would mean that would mean that on the Meteor's run a single engine train would need an extra 13 and a half minutes in travel time. That is insignificant to a train that takes 28 hours to make it's run.

If it takes 4 minutes to reach track speed, we still aren't adding much more in the way of increased travel time.

 

[AlanB]

I have to say that too much power is not always a bad thing. It is possible that a single locomotive that is overworked, especially with acceleration could take about the same amount of fuel as 2 locomotives sharing the work. Fuel cost isn't the only thing to consider, if your burning up locomotives because they are stained constantly, then I dont see where the cost savings would be shown over using 2 units.

I don't think that asking a P42 to haul 10 cars is overworking the engine. I readily admit however, that I'm not an expert in this area. That said though, I routinely see a lash up of two freight engines routinely haul 30 - 40 cars on a local freight line here in Queens. That's 15 to 20 cars to one engine and freight weighs more than passengers.

The same works with cars, The Ford Mustang is a good example of this. The V-6 with 190 HP Mustang only gets about 4 MPG more then it's GT counterpart with a 260 HP engine. The V-8 doesn't have to work as hard as the 6 to do the same job. Of corse getting up to track speed is the hardest work a locomotive encounters, once there it's easy street the rest of the way (except for big grades)

I'll take your numbers as accurate for the Mustang, since I have no knowledge in that area. Let me say a couple of things however about your example. One, you are comparing two different sized engines in your example. In the case of the P42, the engine size remains the same.

Secondly in your example, you are still moving the same amount of weight. Since you didn't mention that, I'm assuming that the car weighs the same. Even if it doesn't, the V-8 doesn't add that much more weight to the car vs. the V-6. In the case of the P42, adding a second engine adds 266,000 more pounds that now have to be moved.

Finally, even in your example you saved fuel with the smaller engine. It may not have been as much as you would have thought you'd save, but you did save fuel. In the example that started this long and interesting discussion, it was stated that having only one engine used a lot more fuel than having two engines, not less.

 

[battalion51]

I don't think that asking a P42 to haul 10 cars is overworking the engine. I readily admit however, that I'm not an expert in this area. That said though, I routinely see a lash up of two freight engines routinely haul 30 - 40 cars on a local freight line here in Queens. That's 15 to 20 cars to one engine and freight weighs more than passengers.

Well you forgot to add another factor in Alan, HEP. A single P42 is not only responsible for pulling the train, but also powering it. Now we still haven't found excat figures, but you will lose 1000-1200 horses for HEP, which puts the overall HP for the engine around 2800-3000. Now if Amtrak had installed a secondary unit for HEP (like they should have) one engine would be fine to haul these trains. But it's the HEP load that really drags down these trains, and it also wears the engine more. For example, if you ever are on the ground when a train comes into its final stop (overall or for that engine) the Engineers shut down HEP. There is a considerable drop off in engine noise upon HEP shutdown, as the engine goes to true idle. When HEP is fired into the standby position, the engine revs right back up. So, the real truth here, is that HEP keeps these engines firing in the 8th notch all the time, but not all the power is going to the traction motors. If Amtrak were to invest in some Cattepilar engines for HEP (like most Commuter RRs do) one engine for a ten car train would be fine.