TM 5-5420-280-23&P
0030 00
BRIDGE AND PALLET CRACK DEFORMATION INSPECTION AND REPAIR (Contd)
WARNING
Welding repair of bridge structural components is not
allowed at field level. Attempting welding repair of
damaged structural areas without proper heat treating will
compromise strength of bridge. Failure to comply may
result in failure of bridge, damage to equipment, and
possible injury or death to personnel.
NOTE
If there are several cracks or holes within a damaged area,
repair must be performed by removing damaged area and
welding in a new sheet metal plate, P/N AMS-QQ-A-25014,
NSN 9535-00-003-6946.
REB are made from Aluminum Alloy EN AW7020 to
EN-755, EN-485 etc.
PREPARATION
1.
Position bridge (1) so crack (2) is face-up for welding.
2.
Grind area and find ends of crack (2).
3.
Drill a hole (3) at ends of crack (2) in order to prevent enlargement of crack (2). Use a drill
with diameter corresponding to half the plate thickness.
NOTE
If crack is open 0.098 in. (2.5 mm) or more, and additional
permanent weld pool retainer is required. For this retainer,
use a metal strip 1 in. (25.4 mm) or more in width and with
a milled groove.
4.
Mill or grind a V-seam along crack (2) with a groove angle of 70 degrees.
5.
Clean area to be welded with a stainless steel wire brush.
1
3
2
DRILL BIT SIZE IS EQUAL TO
HALF THE PLATE THICKNESS
0030 00-13
