THE DOUBLE SAW BY WAS DIFFICULT ENOUGH IN STEAM DAYS.

Here's a look at the maneuver, using a computer simulation.

Anyone who has ever carried this off in real life, or on a model railroad, where there's play value and a lot of cracking wise going on during the evolution, will have made use of, or at least thought of making use of, that trailing point spur the first train encounters to stash enough of the train to obviate all the to-ing-and-fro-ing that otherwise follows.  "If trains that are both too long for a siding have to meet, it is a very time consuming process, and something that the dispatcher will avoid at all costs."  Figure two hours, and that's with five people available on each train to help with flagging and getting the iron and connecting the air and all the other stuff.

Apparently, though, the existing rash of discouraging traffic by downsizing hasn't driven enough shippers away.

In October CSX Transportation ran two overlength merchandise trains at each other on its single-track mainline between Savannah and Augusta, Ga. The plan was to do a double saw-by — a maneuver as complicated and time-consuming as you can imagine — to get the no-fitters past each other. But that plan went out the window when the 12,000-footer tripped a hot box detector. While the conductor hit the ground to find the problem, the crew of the 11,000-footer was instructed to leave half of its train in a siding, then proceed to the next siding to await the 12,000-footer. Once it passed, the 11,000-footer had to retrace its steps and put its train back together before heading back in the right direction.

The idea behind long trains is as simple as it is old. Move your tonnage on fewer but longer trains and you save crew, locomotive, and fuel costs.

The savings can be illusory, though, if you take the concept to the extreme. In the CSX example, both manifest trains had to be recrewed. So did two locals caught up in the mess. Amtrak’s Silver Star was delayed 45 minutes. And, most importantly, the customers’ freight was delayed almost 5 hours.

These days, there are two crew members per train, the engineer, and the conductor, who is often rated as an engineer as well. Nobody to walk ahead from the caboose, and unless there's somebody from the mechanical department with a pickup truck available to help with the joints and getting the air, there's a lot of walking by a few people, even if you're breaking the shorter train at two sidings, thus creating a single saw-by.

Maybe one of these days the people who look at the financials will see what a false economy the long trains are.

Railroads continue to push the limits of common sense with megatrains. On subdivisions where long sidings are few and far between, the no-fitter trains extend meet delays. Even double-track mains aren’t immune. Monster trains can bog down the double iron by taking longer to enter and exit permanent and temporary speed restrictions. Megatrains also encounter more frequent mechanical problems. The law of averages says that the more cars in a train, the more likely there’s a bad apple in the bunch.

Given all this collateral damage, why would some Class I railroads continue their love affair with trains that don’t fit their physical plants? It’s because they care more about the operating ratio and investors than they do about providing reliable service.

The service design veterans I spoke with agreed it’s bad railroading to run no-fitter trains in both directions in single-track territory. It’s also not a good idea to run lumbering behemoths that turn a fast double-track corridor into molasses. The toll on service simply isn’t worth it. And the supposed operational savings are all too often offset by unpredictability of recrewing trains en route.

Those who do not remember the Chicago Great Western might be compelled to repeat it.