Roadwolf's Blog

It is undeniable that the creation of the GP (General Purpose) 7 changed railroading drastically.  The GP7 units were designed by Dick Dilworth of EMD.  His goal was to make a road switcher which would work well “out where the real work was being done.”  The design was based on observations from Alco and Baldwin Locomotives, as well as considerations of the needs of a freight train crew.

Originally the GP7 was made with limited visibility.  This was partly because the union atmosphere at the time, wanted to keep the fireman on the locomotive, to simply watch the left side.  In reality, Firemen were kept on the crew until the mid 80’s or early 90’s in some cases – strictly due to union pressure.

Another consideration in building the GP7 with long high hoods, and a centrally located drivers cab was the consideration of the old Steam Era Engineers and Firemen.  They often liked the idea of a buffer between them and the front of the train – in case of collision.  Although these hoods were not structural, and would not stop a collision as well as a heavy boiler would, the impression of the high hood did play a key role in how popular the GP7 became.

The other critical aspect which made the GP’s popular was the control stand.  Dilworth brought in locomotive engineers from various railroads, and sat them down as a mock up engine cab.  The Engineers told Dilworth what they wanted.  And Dilworth followed through, to create a control stand, which stands in the middle of the cab, close to the right hand window.  From which the Engineer could easily operate the controls while looking either forward or backwards.  This design became the AAR Standard Control Stand.

EMD Could not produce GP7’s fast enough to keep up with demand, and opened up an Engine Plant in Cleveland, Ohio to try to meet demands.  In total, 2,729 GP7’s were produced.

The GP9 replaced the GP7 in 1954 and ended up becoming even more popular with 3,444 units being sold.  The GP18 made its debut in 1959 and augmented the GP9 until 1963 when both the GP9 and GP18 ceased production.   The GP18 was less popular, with only 350 units being built.

All in all, these GPs or Geeps were the turning point of freight operations in North America.

ITC #1605 GP7 – Photo by Sean Lamb

The Geeps were all very similar looking.  The unique differences are subtle, but easily identifiable.   GP7’s generally have 3 vents below the drivers cab, such as the photo above.   GP7’s also have a pair of grills in the access doors towards the rear of the long hood on each side.  The GP7 also had a skirt covering part of the gas tank, however in late model GP7’s and early model GP9’s the skirt was retained, however with access holes added.  Eventually the skirt was often removed completely later for access.

GTW #4621 GP9 with a short hood

DGVR #40 GP9 with dynamic breaking (as evident by the rounded vent at the top)

The GP9 is identifiable by often just one vent, or small half sized vents below the drivers cab.  The GP9 also only has one set of grills on the access hatch doors at the rear of the long hood.  And 3 sets of double grills on the central access hatch doors of the long hood as well.

An EMD GP18. Photo by Doug Kroll

The GP18 looks very similar to the GP9.  The only exception is the Fuel Fill cap, which is positioned a little higher on the GP18.  Instead of coming out of the Skirt on the GP9, it comes out of the side of the frame / lower walkway portion on the GP18.   The GP18 also had a Roots Pump Supercharger.

The authors favorite Diesel-Electric Locomotive, has to be the GP9 short-hood.  It was the most common locomotive I saw growing up near the CN Lines in and around Toronto, and the fact that the GP9’s are still kicking and in revenue service on several railroads, just proves their worth in my eyes.  These locomotives are beasts which deserve some respect.

In the early days of Steam, and even in the first 30 years of Diesel-Electric locomotives, the challenge for any manufacture of locomotives was to get as much horsepower out of a single unit as possible.  The Horsepower Race for Steam Locomotives fizzled out when Diesel-Electrics started proving their worth during World War II.

One of the biggest selling point for 2nd and 3rd generation diesel-electrics was unit reduction.  Each unit could produce more horsepower then a previous generation of diesel-electrics, and thusly you needed fewer units to move a train.  This worked out well.  As an example:

• In 1962, 6 F unit locomotives could be used together to provide power up to 9,000 horsepower.
• In 1963, The same railroad company bought some GP30’s and used only four GP30’s to produce 9,000 horsepower.
• In 1966, The same railroad company bought some SD40’s and used three per train to produce 9,000 horsepower.

Union Pacific was always ahead of the class in terms of horsepower.  In the 1940’s it produced the 4-8-8-4 Big Boy Steam Locomotive, which was the worlds largest steam locomotive.  Not to be unmatched, it led the race with Diesels as well – often using some unique methods.  One of those methods was to use a Steam-Turbine-Electric system to power a diesel-esque looking locomotive with 2,500 horsepower, which was remarkable in 1939 when they made this happen.  In 1948 the UP used jet engine technology to create a 4,500 horsepower Gas-Turbine-Electric.

In 1958 UP teamed up with GE and created 10 ‘Big Blow’ locomotives, capable of 10,000 horsepower.  These were also Gas-Turbine-Electrics.  The UP was wild about horsepower, and in the 60’s it got Alco, GE and EMD all racing to build the UP the most powerful articulated locomotive possible.   Everyone was reaching for 15,000 horsepower.  EMD in theory won that race, with the DDA40X.  While They didn’t meet the goal, they did pretty darned good for a Diesel-Electric, pumping out 6,600 horsepower per twin engine unit.  Still the most powerful Diesel-Electric single unit locomotive ever produced.

AC Traction was the next biggest thing to come to the Diesel-Electric world.   Of course, AC Traction motors have been around for a long time,  and were known to be very efficient.  The problem was they liked to settle at whatever frequency the AC power was being provided at.  This meant that they were harder to control.  This is where computers came into play, and in the 1980’s this technology was readily available and caused a slew of AC Diesel Electrics to show up on the railroads.

AC Versions of Locomotives were often a few hundred horsepower more then their DC Counterparts.  For example, the SD70M is rated at 4,000 horsepower, while the SD70MAC is rated at about 4,300 horsepower.  EMD built a new engine to be used on AC units called the 265H which was a four cycle engine which could produce in-itself 6,000 horsepower.  This engine was an option in the new SD90MAC.  However only about 40 SD90MAC’s were produced with this new powerplant.

The reason being was that in the late 1990’s many railroads had came to realize that these 6,000 horsepower units were a waste.  Most heavy unit trains these days require a total of 12,000 or so horsepower.  If you are using two 6,000 horsepower locomotives, and one breaks down, you will not have enough power to move that train with just one locomotive.  However with 3 locomotives rated at 4,000 horsepower, chances are you will still have just enough juice to continue to your destination.

AC Traction motors and 4 cycle engines are still being used, however these days not in an effort to win any horsepower races, but more so to reduce fuel consumption.  The GEVO-12 by GE is capable of producing 4,400 horsepower from 12 cylinders.  This is a big improvement to the previous standard engine that GE used to use, which was a 16 cylinder engine, which produced about the same amount of power.

Today the ideal horsepower rating for a single locomotive has been set at around 4,300 horsepower.  And the new race is to reduce fuel consumption and to create ‘greener’ locomotives.

Rail yards are often the hubs of rail activity.  But what is their function?  This article will explore the various types of yards, and their functions.

The Flat Yard

Perhaps the simplest type of rail yard is the common flat yard.   The flat yard is just that,  a flat yard, with tracks which run parallel to each other, connected by a common ladder track (or 2 common ladder tacks, one at each end).  Flat yards can be as small as a simple 1 or 2 track siding used for storing freight cars, to a massive 50 track yard used for classification and sorting.  The key to a flat yard is that all the switching is done manually.  Thus it is a slow and inefficient method for sorting and classifying cars.  In most cases these yards are used as transfer yards between branches or rail carriers, or in industrial areas as staging yards for larger industries.  They are also commonly used for regional/local yards.

Flat yards are often very simple, and use track numbering which is also very simple, often starting ‘track 1′ from the closest parallel track from the main line, and working out from there.   It is also rare for a flat yard to have more then 2 ladder tracks.  Busy yards may have 3 or 4 ladder tracks (two on each side, to allow two classification jobs to work the yard at the same time), however most only have 2 – one on each side.   Flat yards also rarely have more then one or two main lobes (groupings).  There is almost always a running track in flat yards as well.  A running tack is a track which is designated to always be kept clear of stationary rolling stock so as to allow rains to pass through the yard within the yard limits.  Note that this is not the same as a mainline track which may parallel the yard, as to use the main line would require leaving the yard limits in most cases.

Hump Yard

A Hump Yard is a modern sorting facility.  Think of a Hump Yard as a grand terminal of freight.  This is where most modern freight gets sorted and classified.  Every major city has at least one Hump Yard near it, as a general rule of thumb – but as railroads modernize and streamline their operations, they have been eliminating smaller and less productive hump yards where possible.

The Hump Yard is actually a combination of flat yards and hump yards alike to create a flowing system.  Often there will be a group of receiving tracks which will consist of a flat yard where trains can pull into.

The locomotives of these trains will detach from their consist, and often will head to a locomotive facility for refueling and reassignment.  The locomotive shop is also another aspect of most hump yards, and is a small flat yard used for servicing.

A local yard switcher will connect to the consist of cars that the incoming train left on the receiving tracks, and then will direct it to a ‘hump’ which is where the train will be sorted into new trains.  The switcher pushes the string of cars over the hump, which is often a small hill.  Gravity propels the cars down the hill and into an electrically controlled yard.  Switches at the mouth of the hump yard are operated remotely, often with the aid of a computerized system which knows what track the next car needs to be in.  The car, now free of its former train, rolls into the correct track in the classification bowl to be included in a train to its new destination.  Devices called Retarders, which are actually stationary breaking systems build into the track, at the mouth of the hump yard, slow the loose cars down to a safe speed as they roll towards their destination track.  This is actually the hump of the hump yard.

From there, a yard switcher will take a string (or rake) of cars out of the classification bowl (hump yard) and place them into a departure yard.  The departure yard is another long flat yard, which is where outgoing trains are assembled from strings of cars made in the classification yard.

In some cases, yards will have more then one hump yard, to serve either local and long haul service, or to serve eastbound and westbound traffic.  If this is the case, these yards will often have separate receiving and departure yards for each.  It is also common to have a yard within a hump yard for local traffic, as well as a yard for car storage.

Intermodal Yard

The Intermodal Yard is becoming one of the busiest types of yards on any rail system.  Intermodal yards are large spread out flat yards, with cranes and hoists to facilitate the loading and unloading of container (COFC – Container on Flat Car) and road trailer (TOFC – Trailer on Flat Car) loads from specially constructed flat cars.

The key to Intermodal operations is that you can completely avoid humping and classifying for the most part.  Trains just run from one Intermodal yard to another, usually as high priority trains, and local loads are removed and sent by truck to their destination.  The rest of the train remains in place and is sent off to another destination.  This streamlines operation.  And while this type of operation kills the classic style of freight railroading we all grew up to enjoy watching, this is one of the biggest money makers in the freight world, and thus it keeps the trains rolling.

The Auto Yard

An Auto Yard is often a flat yard with a single ladder track on one side.   Ramps set at the dead end of each track facilitate the loading and unloading of automobiles into autorack cars.  These yards are usually surrounded by a vast sea of new cars in a large parking lot.

That basically covers all of the train yards in use today.