Name the maximum thickness of soil layers when compaction is done by hand - NSC Civil Technology Civil Services - Question 4 - 2023 - Paper 1

The lid of a concrete ring manhole that is deeper than 750 mm should be set with a rubber seal or gasket in the groove of the lid to prevent water and gas ingress, ensuring that it is tightly sealed when installed.

The standard length of engineered bricks used in manhole construction is typically 230 mm.

A two-dimensional sketch would include a depiction of bracing or shoring systems such as timber or metal props to uphold the sides of the excavation, ensuring stability and preventing collapses.

A spirit level or a surveying level is the tool that can be used to ensure the correct slope of a drain pipe over a short distance.

A designated safety officer or a supervisor must monitor the free end of the rope attached to the safety harness of the worker to ensure safety during operations.

First, a risk assessment must be performed to determine any hazardous conditions that may exist within the confined space. Second, continuous atmospheric monitoring must be conducted to ensure that oxygen levels and potential toxic gases are within safe limits before entry.

First, the use of proper fall protection systems such as harnesses and guardrails is mandatory. Second, workers must be trained in the safe use of ladders and scaffolding according to local safety regulations.

To calculate the volume of the tank in cubic meters:

$ext{Volume} = ext{Length} imes ext{Width} imes ext{Height}$

$ext{Volume} = 3.7 imes 3.7 imes 3.7 = 50.653 m³$

To convert the volume to litres, use the conversion factor of 1000 litres per cubic meter:

$ext{Volume in litres} = 50.653 m³ imes 1000 = 50653 litres$

The volume of the tank is 50.653 m³.

The volume of the tank is 50653 litres.