Wednesday, March 25, 2015

MoW: Track Ballast Tamper and Stoneblower

(Update: near the end of a time-lapse video shows a tamper and ballast regulator along with a ballast dump train after the installation of some new track.)

Video at 12:32
After years of use, the track ballast (the rocks around the ties) settles and the tracks can become uneven. Or the tracks are straight until the wheels of a car passes over them and they "pump" up and down. That is, the ballast is no longer properly supporting the ties. Last year I could have walked down to the BNSF/CB&Q tracks close to my house and take a video of ties pumping as a train passed. But BNSF did track work last summer and, fortunately, I can no longer easily get a video of track pumping. One of the machines, a ballast tamper, is of interest because of the many hydraulic actuators it uses.
Video at 0:15
This video shows a single-tie tamper. At timestamp 0:12 note the carriage it pushes in front of it. This is a projector buggy [term comes from comments in a posting and verified by a manufacture's documentation] so that it can measure the heights of the rails. At 0:19 you see a gripper come down below the head of the track and raise the rail. And then the "fingers" that go into the ballast to shove some ballast under the tie, one tie at a time. 0:58 shows what you can see in the other scenes as well, a ballast regulator has already made a pass over the rail to shove ballast on top of the ties. At 1:06 we see the ballast regulator working on removing the unused ballast from the ties. 1:18 is a sequence of the gripper and fingers in action. You can see that the fingers go into the ballast, and then move towards each other to squeeze ballast under the tie. What is harder to see is that the fingers vibrate as they squeeze.
Video at 1:57
The actuator seen at 1:57 is probably a vibrator. And at the top of the vibrator is the hydraulic ram that squeezes the fingers together. Then in the overview shot, say 2:05, you can see that there would be a hydraulic ram that raises and lowers the finger carriage. You can also see that control of all of the hydraulic actuators and the movement of the vehicle forwards is controlled by a computer because the operator is just standing and looking for problems. Then at 2:22 we see the ballast regulator cleaning up the tracks.
Video at10:14
They had to close a road at the crossing and remove the road filler because the far rail dips so badly you can see the dip without needing a projector buggy.

A video of a unit that does three ties at a time with a movable carriage so that the unit itself advances in a continuous motion.

Video at 0:14
When the ballast tamper is in transport mode, the bars that push the target ahead of it are folded up and the target is carried instead of pushed.

Micky Cecil posted
[Sometimes you need some more ballast before you can bring in the tamper. Is the guy trying to see if it is bent sideways as well as down? Where is the hard hat and safety vest?]
Joe Dockrill posted
FYI for those that don't know what a tamper does or how it works:
Tamping tines pack the ballast under the sleeper to produce a stable sleeper bed.
Plasser & Theurer developed a mechanised technique for this purpose: the system of non-synchronous constant pressure tamping which in professional circles is regarded as pioneering and unequalled in quality. The tamping tines penetrate the ballast bed from above and compact the ballast under the sleeper with a squeezing movement. Two factors are decisive here. Firstly, all tamping tines work with the same pressure; and secondly, the tamping tines vibrate with the ideal frequency of exactly 35 Hz. This directional, linear vibration combined with the non-synchronous tine movement produces a homogeneously compacted ballast bed.
[It is a shame the group is closed because many of the comments were informative.]
Jdoc Jdoc shared
Fred Bain Humm... taken from the clamp frame looking back. Obviously a switch capable tamper.
Screenshot, -0:53
When I watched this video of a 3-tie moving carriage tamper, I wondered who/how someone is watching the tamping. Also, I don't know what the second machine does. If they are working on a commuter route, that would explain why they can get a MoW work window only at night.

In this screenshot, note the two wheels in the lower-left corner that catch the rail under its flange and lift it to the correct height. Also note the hoses in the upper-left for all of the hydraulic circuits that are needed to operate the machine.
Then I came across a posting of this video (-2:00) showing that the operator rides under the machine behind the carriage. Note that he has a camera screen in the upper middle so that he can make sure the flange wheel is doing its job of lifting the rail.
Dom Rosso posted two photos with the comment: "Our old 4x4 and the switch tamper that does most of its work nowadays."


David Brumley posted two photos with the comment: "Triple head plasser!"

(new window)

Then Jdoc posted this video with the comment "little mud spot tamping. not mine, 3X tamper. another exclusive video........." I don't know if this is a closeup of what is happening in the second unit or if this is the first unit used in a different (touch up) mode.

(new window)  (source1, source2)
Frederick Keys T32 prototype joe, there's a video of it working online. Harscos first tamper with a wire lifting system instead of the double barrel. [Unfortunately, I don't understand what "wire lifting" and "double barrel" means.]
Stan Sandstrom Clifford is correct regarding the wire lift and line. It also has Youngman Positive Dislacement workheads which were developed in Australia. This machine is likely either in New Zealand or Australia.
Damien Smith Stan Sandstrom this machines was built in the states but yes the heads are Australian designed.
Frederick Keys 32 tool continuous action, not quite a 09-32 but they've had a fair crack at it. [The UP Plasser American pictured above may be the 09-32 that he is referring to.]
[I don't see the telescoping projector buggy at one end that I associate with tampers.]

Evidently a stoneblower makes tampers obsolete even though fancier tampers are still being designed. American railroads like to brag about their innovative technologies (a recent example), yet they won't try a stoneblower.
(new window)   (source)
Fred Bain Quite the concept. Treat just the wounded and don't disturb the ballast.
Stan Sandstrom Its a great machine. Harsco sold a lot of them in the UK. Unfortunately no US Railroad would try one. Two reasons I heard were 1. Some customers thought it wouldn't work on heavy haul track 2. They are very expensive and Harsco management didn't want to build one as a demo unit and no railroad wanted to buy one without a long trial period before purchasing. Only harscos sales department knows for sure.
(April 2019 Update: Harsco still has an icon on their videos page, but it is also broke.

So I have to switch to a text and photo description. [HarscoRail-web]


  • Pneumatically injects ballast under the tie to achieve track position accuracy of 1.0 mm without disturbing the pre-existing compacted foundation
  • Track remains in position much longer than track maintained by traditional tamping methods
  • Track immediately opened at line speed after stoneblowing
  • Post maintenance record of quality immediately available
  • On-board crane loads machine completely with stone in less than one hour
Harsco Brochure
Harsco Brochure

Joe Dockrill shared
stoneblower, a different type of surfacing, minor surface deviation correction by injecting stones

Ram Busse posted four photos and a video.

Joe Dockrill shared
Phil Kirkland Fire suppression system failure?
Kyle Dunbar Runaway Cummings!! 😂




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