Switch blades, crossing frogs, point rods and other crossing pieces

73.02 - Railway or tramwa track construction material of iron or steel, the following : rails, check-rails an rack rails, switch blades, crossing frogs, point rods and other crossing pieces, sleepers (cross-ties), fish-plates, chairs, chair wedges, sole plates base plates), rail clips, bedplates, ties and other material specialized for joinhng or xing rails. il k 7302.10 - Rails 7302.30 - Switch blades, crossing frogs, point rods and other crossing pieces 7302.40 - Fish-plates and sole plates 7302.90 - Other This heading covers iron or steel railway and tramway track construction material, whether of normal or narrow gauge. (1) Rails for railwa s or trarnwa s are hot-rolled roducts. The heading covers all len hs of such rails inclu ing bull hea rails, flange (or at-bottomed) rails, grooved tram rai s, slot rails for electric tramways, and conductor-rails, etc. d' fi d' gt This heading covers all rails of the type normally used for railway or trimway track, irrespective of their intended use (over-head transporters, mobile cranes, etc.). It does not, however, cover rails not of the railway or tramway type (e.g., sliding door rails and lift rails). Check-rails, also known as guard rails or safety rails, are fixed to track rails to prevent derailments at crossings and curves. Rack rails are intended for steep gradient railways. One type consists of two long parallel bars connected by closely spaced transverse rods; the spaces between these rods are designed to engage the teeth of the cogged wheel beneath the locomotive. A second type conslsts of a toothed rail which engages similarly with the cogged wheel. All the above rails may be straight, curved or drilled with bolt holes. (2) Switch blades, crossing frogs, point rods and other crossing ieces which may be cast or otherwise obtained, are used at the junctions or intersections o!i' the permanent way. (3) Iron or steel " sleepers " (cross-ties) are used to support the rails and keep them parallel. They are usually pressed into final shape after rolling, but they may also be assembled by welding or riveting several elements together. They normally have a cross-section in the form of a " U " or a very short-legged ca ital omega, and they remain in the headii whether or not drilled, punched, slotted, or tted with chairs or sole plates, or with integra formed rail fastening housings. R (4) Fish- lates are hot-rolled, forged or cast products of various shapes (flat, shouldered, an l e t etc.) used for jointing one rail to the next. They fall in the heading whether or not drt led or punched. (5) Chairs (usually of cast iron) are used to fix bull-head rails to the sleepers; they are secured by coach screws or bolts. Chair wedges are used to hold the rails in the chairs. Sole plates (base lates, sleeper plates) are used in fvring flat-bottomed rails to sleepers. They protect the s eepers and are fixed to them by cramps, bolts, coach screws, spikes or, in the case of steel, by welding. f Rail clips are likewise used to fix flat-bottomed rails to the sleepers; they are bolted to the sleepers and clamp the flat bottom of the rail to them. The heading also covem other rigid railway rail f d n g devices, such as those obtained by bending a steel bar into an approximate L-shape, the shortest side pressing against the flan e of the rail and the Ion est side, with its end slightly flattened but not pointed, being fixe in a hole previously dri ed in the sleeper. ti Furthermore, resilient rail fastening devices are covered by this headin These are manufactured from spring steel and clam the rail to the sleeper or sole plate. h e clamping force is obtained by a geornetricaf deflection of the fastening from the" as manufactured " condition. A pad or insulating device, usually of rubber or plastics, is interposed between the fastening and the rail or the fastening and the sleeper. (6) Bedplates and ties are used to fix the rails in their parallel position. Some special s acin -ties and angle-bars are desi ed to be bolted on to a number of successive woo en s cepers; being thus fixed at angles to the sleepers they serve to prevent deformation (01- " creep ") of the track at certain points. $ f rig (7) Other specialised raid anchors are devices attached or clamped to the rail where lon 'tudinal creep occ~us.These bear against the sleeper or sole plate tending to prevent suc longitudinal movement. R The heading does not cover : Screws, bolts, nuts, rivets and spikes used for fixing track construction materials (beadings 73.17 and 73.18). (b) Assembled track, turntables, platform buffers and loading gauges (heading 86.08).