Along some track near a bike trail I saw a big pile of rubber rectangles the size and shape of tie plates. They were about 3/8" thick and black, with holes that matched where spikes would have been driven through. None of the tie plates in sight had any of the rubber rectangles under them. What would be their purpose? Just shims when needed? Are they made of rubber for some cushioning effect?
Adze pads (abrasion pads) - sounds like the insulated type (don’t work worth a crap) …somewhere in a crossing approach circuit?
With holes in them, probably used or failed. (crapped out, leftover after a tie gang went through?) Signalmen like 'em, trackmen would rather do without.
Concrete tie version is smaller and thicker than the wood version. Rail seat abrasion/wear and cant issues in concrete ties are a constant headache. In addition. the reinforcing steel cable in pre-stressed concrete ties fails faster with induced current in the tie.
Now I can’t get “rubber biscuits” outa my head.[%-)]
From http://www.senecarail.com/track-materials
"tie pads form a tough, resilient layer between the tie and steel plate, which helps prevent tie cutting, muffles noise and cushions vibration. In addition to being highly resistant to ozone, chemicals and weathering, Seneca tie pads are low cost and can increase savings on your track maintenance programs. Tie pads also help to reduce the loosening of track bolts, joints and spikes in tie plates. Tie pads are the low cost way to save on track maintenance.
Their pads are a combination of rubber and fiber. Another company Noble Rubber Corp, http://bridgetiepad.com/ makes theirs from recycled tires.
It’s nice to know that something else is made from recycled tires besides hockey pucks.
Apparently you never have been to Texas with their crumble rubber asphalt (good stuff), gone over an OMNI rubber grade crossing or seen the current “prescription” artificial turf on a ballfield.
Can’t … get… “rubber biscuits” …out of…my…head…[banghead][banghead][banghead]…aaaaargh!
You’ve got my attention; I never would have imagined that this would be a problem. What would induce current in the cables? Fields from nearby power transmission lines? I was thinking stray fields from traction motors, but they are only there for a short time. Does the induced current cause the steel to heat up?
It doesn’t take much and I don’t really know the source. Details come from materials testing on failed pre-stressed concrete ties. It has become an issue in places in the industry, especially in the bonding interface between the polymer concrete and the pre-stressed wire rope.
Mudchicken said, and Murphy S., noted in his Thread: “…Can’t … get… “rubber biscuits” …out of…my…head…aaaaargh!..”
Yep, MC…‘Rubber Biscuits’ have a special meaning. [:-^]
Ummm…is Duncan a finicky eater?
And now to properly credit the original artist:
The recycled crumbled rubber tire remnants are also converted into sidewalk ‘paving’ by a local company.
He nibbles like most scotties. Not that picky though…
(OTOH, Gus was a Hoover.)
I’ll take a wild guess and speculate that it may be the result of the alternating current in the rails that’s used for both the block signal circuits and the grade crossing circuits (different frequencies). As I understand it, the continuously varying AC creates a changing magnetic field, which induces an electrical current in anything metal nearby - such as the pre-stressing cables in the ties. Depending on whether the cables are coated and with what, that current may then cause a galvanic reaction and lead to corrosion of the cables, at least on the surface which is exposed to the concrete - which is where the bond between them is most critical.
I’ll certainly defer to anyone with a better technical understanding of this.
Murphy: Is there a bridge with an open timber deck nearby ? Sometimes the pads are used there for many of the same reasons that are mentioned above by other posters.
- PDN.
Bet they go well with rubber chickens.[dinner]
No it’s by a crossing over a busy city street. It runs through a city park with a bike trail right next to it. The parks department got ambitious and mowed right up to the ballast. That’s why I noticed the rubber biscuits.
That brings up another thought. Why do railroads tend to just leave things in piles- like thes rubber biscuits, tie plates and spikes? They
The best way to get rid of an ear-worm song is to replace it with another one like…
Who let the dogs out? Who? Who? Who?
Who let the dogs out? Who? Who? Who?[:-,]
Hey, I might resemble that remark!
Thanks, Paul North. I hadn’t thought about the current for the signal circuits.
One thing I did think about was back in the late '60’s when computer memories were almost exclusively core, the company I worked for developed plated wire memory which could be made for considerably less cost. The wires were plated with a thin magnetic coating that would be polarized in either direction in small spots by other wires running across them in close proximity. They had problems early in the program when the soft epoxy that held the wires in place was too hard. The metal actually expands slightly when magnetized, and the hard epoxy was preventing it from switching polarity. I doubt that this slight expansion would be a problem at the scale we’re talking about for ties, but it brought back some memories.
Guys think MC will pass this lexicon onto the boys in the field ? Something new for the work gangs ?
the term is already used with certain types of direct fixation transit track primarily in subways.
I’d rather credit these guys in this particular context:
hoo hoo hoo hoo hoo … What do you all want for nothin’?
(Aren’t ricochet biscuits the components needed to fix screw fixation systems?)