The tie replacement operation that was going on around the Winthrop Street bridge and will, no doubt, resume north of Winthrop Street Monday morning is quite a sight to see (and hear). There is a pretty good viewing platform from Piggott Road, where they will probably be by Monday afternoon. This is a reasonably accurate description of the parade that marches down the track much like a movable assembly line:

1. A dedicated machine, riding on the tracks, that removes the spikes.
2. Followed by another dedicated machine that knocks out the plates that separate the rails from the ties out from under the rails.
3. Followed by another machine, that reaches down and just pulls the tie out from under the rail and discards it up on the side of the ROW.
4. Followed by another seemingly identical machine that, one-by-one, takes a half-dozen or so new ties and puts them on top of the rails at roughly the location where they will eventually be placed under the rails. This machine then backs off.
5. At this point, the first manual process occurs. A guy grabs a jig and places it in turn on each new tie that’s perched atop the rails and marks a line (on two adjacent faces of each tie) a couple of feet from the end with a piece of chalk.
6. The machine from step 4 returns and, in turn, puts each new tie alongside the outside rail, perpendicular to the rail, with one end of the tie stuffed up under the outside rail. This machine then rolls off over the poorly-supported rails never to be seen again.
7. The next machine is the brute of the lot. I advances one tie at a time and grabs the tie that’s been positioned in step 6 and, by sheer brute force … no wiggling, no jiggling, no shaking, no finesse … just stuffs the new tie up under the rails, dislodging the ballast as if it were Styrofoam packing peanuts. I assume it uses the chalk marks form step 5 to gauge where to position the tie. Then it moves on.
8. The next machine acts a lot like a tamper, which scrunches the ballast up under the ties, but instead of scrunching, it seems instead just to vibrate the newly-placed tie and the ballast underneath it. (I’m a little unclear where in the procession this machine appeared but I’m sure that it did appear.)
9. The second manual operation is a crew of four or five guys with things that look like many-tined hay forks. They dig the ballast out from between the rail and the new tie and make a little depression alongside the tie where some other guys place the plates that were removed in 2.
10. Another machine (the lightest-weight of them all) rolls up, grabs the rail then, lowering some feet onto one of the ties, lifts up on the rail so that the workers can slide the plates into place. Away they all go.
11. The next machine proceeds to drill through the holes in the plates into the new ties, advancing a tie at a time.
12. Followed by a machine that you can’t see what’s going on underneath but that’s loud with much banging and rattling. When that machine rolls away, there are three spikes holding each plate to the ties, six spikes per tie but the rail is still just sitting atop the plate.
13. Along comes another manual crew with sledge hammers and they drive in these huge paper-clip-looking affairs that, I guess, clamp the rails to the plates.
14. Next in the procession seems to be the “school bus”. It doesn’t seem to have any function in the tie replacement process. I think the crew rode to/from the work site on it.
15. The caboose in this affair seems to have a big rotary broom that dresses the ballast neatly and pushes the debris away from the rails.
16. The job I want – there were two guys one at each end of the circus train with this job – involves waiting for a train to come along. At that point, he holds up a round sign with a W on it and all the machines in the procession sound their horns along with the horns of the approaching train. (With my iPod playing, too … it might have been Charlie Parker, this came out a lot like a Charles Ives composition.) All activity stops (a lot like on a military base when they sound To The Colors over the public address system indicating that they’re lowering the flag).