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Clamp, link, pulley: the 3 headspan genders (a #railwaysExplained thread)
A few of the #OLEbook images are a bit meh. So yesterday I went out on a trip to West Ealing to pick up some better ones. In this case, headspan supports.
But 1st, a refresher on along-track movement
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A few of the #OLEbook images are a bit meh. So yesterday I went out on a trip to West Ealing to pick up some better ones. In this case, headspan supports.
But 1st, a refresher on along-track movement
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All OLE systems have to deal with the phenomenon of along-track movement - the amount of expansion and contraction the wires experience as wire temperature varies, due to ambient heating/cooling from solar gain and wind, and also current heating due to electrical load
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All modern mainline systems deal with this by using auto-tensioning; a device is provided at each end of the wire which provides a constant tension. Weights or springs are used, & the wires are able to expand / contract around a fixed central point - the midpoint anchor (MPA)
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