Today’s (and yesterdays’) train-and-watch postings
Today is rail welding and snowed-in-switchyard clearing](http://www.network54.com/Forum/78440/thread/1155916228/Fridays+Railroad+Pics+-+a+little+different..):
CWR is held in place a lot more firmly than regular jointed rail.. Since welded track has very few expansion joints, if no special measures are taken, it could become distorted in hot/cold weather and cause a derailment. To avoid this, welded rail is laid on concrete or steel ties,to hold the rails firmly in place with special attachments (not just spikes anymore), and with more and heavier ballast to stop tie creep. After new segments of rail are laid, or defective rails replaced (welded in), the rails are artificially stressed. The stressing process, involves either heating the rails causing them to expand, or stretching the rails with hydraulic equipment. They are then fastened (clipped) to the sleepers in their expanded form. This ensures that the rail will not expand much further in subsequent hot weather. In cold weather the rails try to contract, but because they are firmly fastened, cannot do so. In effect, stressed rails are a bit like a piece of stretched elastic firmly fastened down. There are also normal joints spaced out between long sections of welded rail.. Advantage is a stronger railbed, which can withstand heavier trains and higher speeds.
Yesterday’s has a spectacular picture from the driver’s seat: [
(Click for full-size version)
One of the regulars in the Seiko and Citizen watch forum is a train engineer and has some marvelous postings. Today’s is on welding rails, and how they are stretched to deal with thermal expansion and high-speed trains. Supercool!