* 3.16.6 Baffles. Unless a lined tank is furnished, the tank shall be furnished with interior
baffles. Not less than two baffles shall be provided. Baffles shall be flanged and dished. Half or
full round openings, top bottom, of not less than 3.3375 inch minimum radius shall be provided
in each baffle. Equivalent area openings shall be provided at the 3 o'clock and 9 o'clock
positions of the baffles. Each baffle shall also be provided with not less than an 18 inch diameter
manway opening. The edges of all baffle openings shall have a flange of approximately 1 inch.
* 3.16.7 Rear manhole. The top rear end of the tank shall be provided with a manhole opening
not less than 18 inches in diameter. A light weight, liquid tight, easy opening, locking manhole
cover or a bolted cover with a liquid tight easy opening, locking fill cover not less than 10 inches
in diameter shall be supplied. The fill opening shall be provided with a removable screen basket
not more than 36 inches deep. The screen basket screen openings shall be not more than
0.50 inch square. The screen basket shall be utilized to catch rags or other solid waste when
loading the tank. Hinged covers shall be hinged at the forward edge.
3.16.8 Front manhole. When specified (see 6.2), the top front end of the tank shall be
provided with a second manhole, identical to that specified in 3.16.7, except that the fill opening
and basket screen are not required.
3.16.9 Flashing boxes. Combination flashing and overturn protection boxes shall be
provided around each manhole. Each box shall be provided with two drain lines, discharging
toward the ground under the tank.
* 3.16.10 Platforms and ladders. A platform approximately 30 inches below the flashing box
shall be provided on the curbside, extending from the front to the rear flashing box. The
platform shall be fabricated from non-skid metal grating not less than 18 inches wide. The
platform shall be provided with guard rails. Steel rung ladders with handholds shall extend from
the top of the tank to the platform and down to the top of the curbside fender (rear ladder) or
bottom of the tank (front ladder)
3.16.11 Top cleanouts. At the top front of the tank and at the top rear of each baffle,
provisions for inserting cleanout tools shall be provided. The cleanouts shall be 3 inch nipples
with blank, bolted on flanges. A front cleanout is not required when front manhole is furnished.
* 3.16.12 Safety vents. The safety vents required by DoT Safety Regulation 178.348,
Specification DOT-412, shall be installed at the appropriate longitudinal location on the tank. A
cover hose assembly to direct the safety vent discharge toward the ground, under the tank, shall
* 3.16.13 Tank Support. Support of tank shall conform to DoT Safety Regulation 178.345-6.
Tank semitrailers provided with continuous external frame type construction shall have supports
directly under each bulkhead, baffle, and at the front and rear of the tank. Adequate support