Safety code for dress divers in civil engineering works
1982 Edition

According to the standard, divers must be at least 18 years old and medically certified fit for diving by a qualified doctor within the past six months. They are also required to undergo chest and bone X-rays annually and pass a pressure endurance test matching the maximum working depth in diving gear or a compression chamber. Additionally, divers should have comprehensive knowledge of diving signals to ensure safe underwater communication.

The diving supervisor is responsible for overseeing all diving activities, ensuring compliance with the safety standard and decompression procedures, including the operation of recompression chambers. They assign tasks within the diving team, verify the presence of adequate signalmen and standby divers, thoroughly inspect all equipment before use, maintain clear communication with divers via lifelines and signals, set up a surface control station prior to diving, monitor diver conditions, and prohibit diving under unsafe conditions such as after alcohol consumption or heavy meals.

Routine maintenance includes daily inspection of the helmet's non-return inlet valve for damage to screws and bearings to maintain airtight seals. Telephone communication connections should be checked daily to prevent loose contacts, and care must be taken to avoid moisture damage to diaphragms. Divers must be trained in the proper use of helmets, including air supply management and underwater navigation. Though not explicitly detailed in the standard, regular rinsing of suits with fresh water after use and checking seals and joints for wear is advisable to maintain equipment integrity.

The standard specifies a minimum air supply of 45 litres per minute per diver under normal conditions, increasing to 75 litres per minute for strenuous work. The total compressor output must be calculated by multiplying the diver’s air demand by the absolute pressure at depth. Compressors should supply air for at least two divers simultaneously at the maximum operational depth, with adequate receiver capacity to support emergency surfacing if compressor failure occurs. Air must be respirable and uncontaminated, with compressors and hoses dedicated solely to breathing air. Divers are also required to carry two bailout cylinders each for emergency air supply.

Decompression times are determined based on dive depth and duration. No limits exist for dives up to 18 meters, with a fixed decompression time of 35 minutes. For depths exceeding 18 meters, maximum allowable dive durations before ascent and associated decompression times are detailed in tables within the standard. For depths up to 35 meters, decompression follows IS 4138-1977 tables, with an additional 5 minutes added for dives beyond 35 meters. Decompression can be conducted underwater or in a medical lock. For diving at altitude, depth adjustments are made by increasing the actual depth by a percentage depending on elevation.