Method of organization: Alternative

Tone: Serious, informative, specific

Note: Created for the general public and other railroading admirers taken into consideration.

Capable of pulling thousands of metric tons of cargo, the diesel locomotives are the monsters of transportation in our world today. From freight to passenger, from station to yards, whether it's hauling coal or mail, diesel locomotives have been servicing mankind's needs to displace unimaginable quantities of cargo. The basic schematic of a diesel locomotive is the prime mover (engine itself) which powers an alternator that supplies electric current to axle mounted electric traction motors. Nevertheless there are two types of electric motors which locomotive companies have to choose from: motors that run on direct current (DC) where electricity flows from a negative borne to a positive one and motors that run on alternating current (AC) where an electric current reverses direction in a circuit at regular intervals. To find out which one of them will best suit a company, they will have to be contrasted in terms of 'power and reliability', and 'cost'.

Cost, as will be seen, is as much an issue than power and reliability. Although AC locomotives are more reliable, have more power and can create unit reduction, not everyone is sold on the AC advantage. In fact, a few major railroads, most notably Canadian National and Norfolk Southern have bypassed on AC's altogether. "It's not for us" says CN, citing favorable gradients and shorter train sizes that just don't justify the extra expense of AC diesels. "At speeds above 11 mph" says a CN representative, "The unit reduction factor afforded with AC isn't an issue ." His boss agrees. CN president Paul Tellier is on the record stating that CN has no current need for AC locomotives. Ultra-conservative Norfolk Southern has likewise shied away from AC, despite all its heavy-haul coal traffic. DC locomotives are much less expensive, almost ¼ of the price of its competitor, and have a higher life span than AC locomotives. Although DC has a lot of disadvantages, for some companies, power, adhesion and unit reduction are not even an issue. Passenger carriers also prefer DC traction engines. "AC doesn't bring anything to the table" says Amtrak test engineer Jeff Laymon. Light, fast trains do not need high adhesion AC offers. Many companies like Amtrak, Via and most commuter trains in North America require only a single unit, so unit reduction isn't a factor and reliability concerns work against reducing units on big long haul trains. Referring to the durabili

Some common words found in the essay are:
North America, Mechanically AC, Note Created, Norfolk Southern, Unlike AC, It's CN, Topic AC, Paul Tellier, Laymon Light, unit reduction, power reliability, traction motors, ac locomotives, Amtrak Via, ac motors, companies choose, dc motors, ac diesels, ac traction, dc traction, steel brushes commutators, ground relays dc, ac traction motors,
Approximate Word count = 988
Approximate Pages = 4 (250 words per page double spaced)