Diving Operations

Introduction

• Used in place of Cofferdams & Caissons

• Can be used WITH cofferdams & caissons

• Need to consider state of water

– Is there a danger of blow-out?

– If yes consider U/W operations

• The deeper the water the more technology required and less complicated work achieved

Practicalities

• Safety Regulations

• Transportation of men and materials

– Barges, pontoons, safety boats

• Tide and current

• Visibility

• Depth

Nature and Extent of Work

• Excavations

– Crane & grab

– Air lift & baskets

• Concreting

– Yes – requires special mix design

– Formwork – same as on dry land

– Tremi –pipe

– Skip

– Pumping

• Sandbagging

Plant & Tools

• Most Pneumatic tools can be used

– Drills,scabblers, picks

– Chainsaws

– Cutters

– Concrete vibrators

• Bolt cutters

• Cutting gear (oxy –hydrogen)

• Thermic lances

• Portable air-lifts

• Lights & camera

• CCTV

• Ropes & shackles

• Lifting bags

Diving Equipment

• The diver:

– Dry-suit and liner

– Kirby-Morgan Band Mask

– AGA Mask

• Surface Demand

• SCUBA

Diving Costs

• DSV (Diving Support Vessel), 12 man team + vessel

– £65K to £75K per day

– Inshore civils work

• up to £30,000 per day

• Equipment costs:

– Kirby Morgan helmet £5000

– Complete diver kit £15000