I just came back from visiting the Panama Canal, and I was wondering what’s the real difference between mules and cummon locomotives. I’ve also noted that the C&O had mules and looked very similar to the ones used at the Canal.
If not mistaken don’t mules have teeth on the rails?
That begs the question: How many different farm animals are there on a railroad? You just mentioned one, the mule. There’s the 0-8-0 “Yard goat”. Don’t forget the SW7 “cow”. Are there any others?
One’s called an ‘Iron Horse’. ( No Sh…t)
The SW7 you mention, tstage, is an example of a “cow & calf” arrangement–a diesel power unit with a cab, and one without.
“Yard goat” is also a general term for any yard switcher, regardless of wheel configuration.
I assume the poster above is referring to mule trains, which aren’t quite the same thing as mule-drawn or horse-drawn railroad cars, which were used in the early days of railroading and public transit…the steam engine replaced the horse in that respect, thus the “iron horse.”
It’s not really clear what the original poster is talking about–by “mules” are you talking about the long-eared things, or some sort of locomotive called a mule?
The locomotives that pull the ships through the Panama Canal locks (rails run along side the locks) are called "mules. Probably a reference back to when actual mules pulled canal boats through the locks on canals in North America.
Here are a couple of good links showing and talking about mules for those of you not familiar with them:
http://www.trainweb.org/panama/loco.html
http://www.galenfrysinger.com/panama_canal_zone.htm
What RedLeader was asking was what is the main difference between these locomotives and regular railroad locos. Unfortunately, the articles I found don’t talk specifically about the engines themselves.
They don’t appear to have a cog rail for traction. I’m trying to figure if they have space enough for a small diesel and generator set under the hood, or if not, where they are picking up the electrical power from.
Regards
Ed
No Cogs but if you look there is a centre rail and looking at the picture of the incline (hump) there must be some kind of mechanism to keep the Mule from slipping.
But I suspect you’re right in regards to where the name came from where mules were originally used to warp the ships through.
Hmm…that link point to them running on 5’ gauge rail (compared to standard rail of 4 feet, 8.5 inches) and having traction equipment. so it may have a geared rail system and considering some of the grades shown in the picutres, it would pretty much have to have at least a cable system to get up them.
Biggest difference seems to be their track gauge.
EDIT: going to this site http://www.pancanal.com/eng/projects/locomotive.html shows a remarkable feature of the sytem, there is a third raises and groved rail in the center, and as i suspect this would be the cog rail. you can see the two stamdard rails are lower and in the ground, but the centeral rail is raised to enter the body of the Mule.
So now we have gauge and a Third rail Cog System as the major differences.
That’s right Ferg, there’s a dented center rail. For the rails along the sides of the locks, the dented center rail is continous. In the service rails, the are dented center rails only at the “humps”. Ed, on the contrary of what people think, the mules don’t pull the vessels, they are only there to prevent the ship from bumping into the concrete walls. The ship moves through the locks by its own means of propultion. About 8 mules are used on a “panamax” type vessel (largest ship that fits the canal locks, shown in the pic).
What is interesting is that the C&O RR also used some kind of mules, and called them mules (like Mule-A shown in the pic below). Notice the device by the side, probably used to tug cars with a cable in yards; I dunno. For what were the C&O mules used for? and why are their cabs so narrow. No third rail in these ones, not in the pics I’ve seen.
The current generation of “Mules’” utilized at the Canal and manufactured by Mitsubishi in several orders, are a 4 wheel electric locomotive configured along the lines of a “steeple cab” interurban loco. The locomotive is powered by two 408v 3 phase squirrel cage type motors. Electric power is drawn via an underground “plow” contact system with two conductor rails buried in a trench running parallel to and outside of one of the running rails. Each contact rail is one phase of the 3 phase system with the running rails providing the third phase conductor. A rack and pinion system is used to produce 100% adhesion when the mule is attached to a vessel transiting the lock as well as to keep the mule from being lifted off of the rails by the movement of the vessel. To accompli***his, the rack is undercut on the sides and the mules are fitted with small steel wheels between the conventional flanged wheels which run in these undercuts. I was the project manager for an engineering firm engaged in redesign of the tow tracks crossover assemblies (basically streetcar turnouts) a couple of years ago and spent extensive time at the canal. It is still the engineering wonder it was 100 years ago.
If anyone is interested in photos of these mules and the tow track details, email me at “bigfrankt@aol.com” and I will forward several.
Frank
Thanks. Nice to have someone who actually knows about this stuff post an answer instead of just having the rest of us guess. It’s amazing who you can find on the forums.
By the way, [#welcome] to the forums!!!
Regards
Ed
If the mule is stubborn you can whip it but if you do the same with a locomotive, you will destroy it or nothing will happen.
Thanks a lot for the great info Bigfrank!! Visiting the canal was so impressive, I went twice in my bussiness trip (company expense har har). Still, are they called mules just because, or ir there a technical difference between a “mule” an a road loco. I mean, besides all of what you explained. Are mules used only for a specific job (like tugging).?
There are Dogs, which is what these things are when they don’t run right.[:D]
The term “Mule” originally referred to the living four legged variety once utilized to pull canal barges through such waterways as the Erie Canal. As the barges were not self propelled and water flow velocity in the canal was nil, a means of propulsion was necessary. Following the development of the steam engine and the subsequent construction of railroads which it enabled, canals and their method of propulsion were phased out as the principal means of moving goods. The term “Mule” as used to refer to the locomotives at the Panama Canal is nothing more than a slang holdover from the early days of canal technology as the Panama Canal always utilized electric locomotives as the means of vessel guidance and to a lesser extent vessel propulsion.