Accel trolley wire for Boston-New Haven electrified rail upgrade

Tom's December 22nd consulting case — 48 hours to evaluate a $6 million copper shipment. Rejected because grain size was too large (too pure). Silver added at 0.2% for strength.

Conductivity — which type of conductivity? Both, that's right, very good. If I take the Amtrak train from Boston to New York — it's an electrical train — it's going to have trolley wire. You go look up and they've got all these ugly towers the whole distance. This is about a 0.545 inch diameter, and it's got a cross section so you can clamp it, and the graphite brushes on top of the train will slide along this thing at 100 miles an hour. So that's trolley wire.

Physical demonstration of a tensile bar made from trolley wire — used to introduce ductile fracture and the critical resolved shear stress. The wire's odd cross-section (round with two grooves for graphite pickup contact) is shown. Tom notes the wire is dilute silver-copper for conductivity plus strength.

There's something called a critical resolved shear stress. If I pull on a bar of material — [Tom holds up a tensile bar of copper.] — I just happen to have a tensile bar of copper. This tensile bar of copper came from a type of wire which has got sort of a weird cross-section. This is trolley wire. If you take the Amtrak Acela train or any other Amtrak train from here to New Haven, Connecticut, the wire that runs AC above the train — they have a little graphite pickup that picks up the electrical energy. It's an electric train, and it's got to have electricity. It doesn't generate its own electricity because you have to have big heavy motors. Essentially you have a sliding contact, and if you're talking Acela at 125 or 150 miles an hour, you've got sliding contact along this wire. It's got these little indents so they can grab it about every 50 feet.