Installation of Ladder

TM 5-5430-209-12

(2) Determine which end of the rails (1 and 2)

will be the bottom. Install steps (4) from bottom toward

top of the ladder.

(3) Four steps (4) make up the assembled

section. Insert bolts (3) through ends of step (4) and

rails (1 and 2) in that order. Install nut (5) on each bolt

(3) protruding through the rails. Tighten bolts after all

steps are installed.

(4) Face the 28-bolthole flange of the

manhole dome (7) and slide it over the top of the rails.

Use a drift pin (3, fig. 3-12) and aline three boltholes at

top of rails with similar holes in side of dome. Insert

bolts (6, fig. 4-7) through rails (1 and 2) and dome (7) in

that order. Apply washers to bolts (6, fig. 4-7). Make

sure cup side of washer is facing down. Install nuts (5)

on bolts (6). Be sure rounded face of nut bears against

the washer. Tighten the bolts.

(5) Install a 30-bolthole gasket (1, fig. 3-21)

on inside face of bottom flange of dome (2). Insert bolts

(3) through flange and gasket. The gasket will hold the

bolts in place.

(6) Install ladder braces (8, fig. 4-7) at bottom

of rails (1 and 2). Place long leg of brace (8) over three

boltholes in vertical leg of the rails. Short leg of the

brace faces outward.

(7) Adjust outside bolting face of short leg so

it measures 9 feet, 2-31/32 inches from top flange of

dome (7). Insert two bolts (3) through each brace (8)

and rails (1 and 2) in that order. Install nuts (5) on bolts

(3) and tighten the bolts.

4-13. Installation of Ladder

a. Line up two diametrically opposite lap seams (1,

fig. 4-8) in tank bottom. Remove nut from each bolt (3,

fig. 4-2) in the lap seams and the first bolt to the right

Figure 4-8. Center support ladder installed.

and left of each lap seam.

b. Raise ladder assembly (fig. 4-7) and set braces

(8) over the bolts. Install and tighten nuts.

4-8