Measuring manhole for RA bills

Unit of measurement

Manholes and chambers is measured in nos. Manholes are usually counted by number for each size and depth band, with extra depth beyond the band measured as the BOQ says.

The BOQ item description decides the unit and what the rate includes. Where the BOQ and this guide differ, the BOQ and the contract's mode of measurement win.

What is measured

• Number of complete manholes of each internal size and type.
• Depth band of each manhole, from invert to the top of the cover.
• Extra depth beyond the deepest band, in rmt or as a separate item where the BOQ provides one.
• Covers and frames, where they are not part of the manhole rate.

Standard deductions

• Incomplete manholes are billed only at a part rate, if the contract allows.
• The depth band follows the invert level on the drawing, as per the contract's mode of measurement and the relevant part of IS 1200.
• Excavation and backfill are counted in the manhole rate or as separate items, never both.

Worked example

Nagpur Municipal storm drain, ward 23, brick manholes 900 mm internal diameter, counted by depth band.

Row by row: Depth up to 1.5 m, 6 = 6; Depth 1.5 to 2.0 m, 4 = 4; Depth 2.0 to 2.5 m, 2 = 2.

Total: 6 plus 4 plus 2 = 12 nos. Deductions are entered with negative nos, so they reduce the total in the same column.

Common disputes

• Depth is measured from ground level instead of from the cover top, moving manholes into a deeper band.
• Manholes without covers are billed as complete.
• Excavation is billed under both the manhole item and the trench item.

Recording it in Tatha Vastu

Each manhole is an entry with its chainage, invert and cover levels and a photo, and the app puts it in the right depth band from the levels.

Approved entries are locked, and a correction becomes a new version with its reason. See the measurement book, or use the measurement sheet template if you still keep the register in Excel.