BRIDGES AND CULVERTS. 43 



culvert pipe? If so, give dimensions required to give 

 ample waterway, and give height from bottom of stream to 

 rail. 



15. See if bed plates and rollers are clean, and if the latter 

 stand so as to move squarely back and forth with the truss. 

 See if pedestal takes an even bearing on rollers. Examine- 

 anchor bolts. 



16. Observe particularly the condition of wall plates where 

 bolster rests upon them. Note any appearance of crushing or 

 decay. 



17. Note condition of bolsters and corbels. See if holes are 

 bored through them where they cover the spaces betweea 

 chord sticks, to prevent the collection of water, and if there 

 is any indication of decay where they are in contact with 

 chord. 



18. Angle blocks and all cast-iron members such as chord - 

 boxes, post shoes, etc., must be examined for cracks and for 

 any indication of displacement by reason of daps splitting or 

 timber crushing. A hole of -J-in. in diameter, if drilled at the 

 end of a crack, will frequently stop its extending farther. 



19. Note particularly any appearance of opening of bottom 

 chord joints. Wooden bridges over- four years old should 

 have gage blocks at all joints in the middle half of the span, 

 made by fastening two planed and squared blocks 1x2 ins., 6 

 ins. long, to the chord sticks with screws, and scribing a fine 

 line across both. Any movement of joints should be noted, 

 giving location and amount, scribing a new line from the old 

 one on the outside block across the inside block. See if clamp 

 daps are shearing. 



20. See that all chord and packing bolts are tight. Nuts 

 on all bolts through guard rails, ties, stringers and floor 

 beams must be secured in place by burring the thread of the 

 bolt at two or three places with a center punch or cape chisel, 



21. Note any signs of decay or crushing in packing blocks, 

 and see that clamps and keys are in proper condition. 



22. See if gib plates are distorted, or crushing into the 

 chords; if they are, give their location and dimensions, num- 

 ber, size and spacing of rods passing through them. Give size 

 of rods over threads. 



