CWR Flashcards
Learn CWR Policy and get good at it. (55 cards)
What is the maximum length for changing CWR rail without destressing?
85’
What is Continuous Welded Rail?
CWR is rail welded into lengths exceeding 400’.
What happens to CWR if joints are added later?
Once CWR is installed, it stays CWR even if joints are added later.
What is the temperature that a piece of CWR is neither in tension or compression?
Rail Neutral Temperature (RNT)
What do you have to do if rail is laid at 40 degrees or more below the TNT?
Rail must be slow ordered or destressed (this is just for laying rail, not installing a plug rail/etc)
Where do we install new anchors?
Wherever needed or necessary.
Where are anchors not required?
Where there are elastic fasteners (safelock clips, pandrol clips, Vossloh, etc)
When are anchors applied on the field side?
If GAP > PULL (i.e. rail is added) then add anchors on the field side for 3 ties in each direction.
What are the two types of anchor patterns and when do we use each?
Standard pattern - normal pattern of boxing every other tie.
Solid box anchor - pattern boxing every tie used when within 195 feet of turnouts, open deck bridges, or other ‘fixed objects’ (Can be crossing with elastic fasteners, for example)
How do you apply anchors on ballast deck bridges?
In the same pattern as the track around it.
How do you apply anchors to open deck bridges?
Apply anchors to all ties fastened to stringers.
How do we anchor around a turnout?
Box anchor the rail anchors for 195 feet ahead of a switch point and behind the heel of a frog on both the main track and the turnout side. For everywhere else, box anchor every second tie.
How do you handle legacy patterns on CWR?
On dual rail installations completed before September 21, 1998, existing anchoring may remain if rail is restrained to prevent track buckles. If restraint is not sufficient, we must adjust rail by increasing or decreasing the length of rail, by lining curves or by adding anchors to rail.
How can the RNT of a string of rail change?
Rail can creep through the fasteners due to train braking, acceleration & temperature changes (anchor/fastener condition dependent).
Curve movement due to curving forces of traffic and temperature swings.
Track settlement under traffic.
Maintenance activities.
What types of maintenance activities may cause RNT changes to CWR track?
Any track disturbance work in curves such as surfacing, tie installation or undercutting (the curve will move inward with cooler temps, outward with warmer temps).
Surfacing where vertical curves or line swings are straightened out.
Rail that is broken or cut for defect repairs or construction activities.
Cutting a plug rail in for adjustments or installations of less than 85 feet.
When is an appropriate time to add rail?
Winter months – when it’s too cold to pull out the gap.
What are the seasons when we shouldn’t add rail?
Transitioning from Spring to Summer, or in the Summer during cool spells at night causing a drastic difference in temperature between night and day.
If you show up to a broken rail and have a 20ft plug rail, how many feet apart should you make your match marks?
28 ft – 20ft plug rail plus 4’ on each side of the joints.
How far from the joint is the match mark required to be?
4ft
When should we de-stress versus pull the amount in the Rail Removal Work Order?
Best practice - if the pull is more than 2 inches, de-stress the rail.
If you’re within 400 feet of a turnout or fixed object, only remove the amount of the original gap or de-stress the rail.
If you de-stress near a fixed objects, de-stress to 10 degrees higher than the TNT.
How do we handle all rail adjustments within 400’ of a fixed object?
All rail adjustments within 400’ of fixed objects are treated one of two ways: De-stress per EI 6.2.4 or Pull the original gap amount (Pull=Gap to restore original match marks).
If rail does not get adjusted properly within the allotted time frame, what is the remedial action?
25mph slow order until properly adjusted.
Can you ever place any other type of slow order besides a 25mph when rail has not been properly adjusted prior to the temperature requirements?
Yes - you can place a 40mph slow order but the location must be inspected DAILY until it is remediated or a 25mph slow is placed.
What are three methods we adjust the rail to TNT or higher?
Using the Pull Chart or pulling the original gap whichever is greater at the time of the initial event
Rail Removal Work Order
De-stress.