Procedure for Entry into Underground Duct Network Revision 0 – 18 th October 2011 Toolbox Talk

INTRODUCTION A pre-entry checklist must be completed before accessing a duct or chamber. Line managers must consider the fitness and suitability of those accessing ducts and chambers. In addition to the hazards associated with working in a potential confined space, there is also a risk of falls from height, injury from falling objects, and, contact with hot surfaces.

TASKS COVERED BY THIS PROCEDURE General duct inspections Isolation of steam or heating system valves Emergency lighting checks and repairs General area lighting checks and repairs Sump pump checks and repairs Running cables

PERSONAL PROTECTIVE EQUIPMENT Required at all times Climber’s helmet which complies with EN 397 Head torch (fully charged) Long sleeved boilersuit Protective gloves Harness (those in the duct and standby man) Safety wellington boots (those in the duct) May be required Knee pads (if crawling around) Thermally rated gloves and sleeves (if likely to be in contact with exposed hot pipework)

WORK EQUIPMENT REQUIRED Gas detectors : 1 Crowcon Tetra gas monitor with extension tubes with the standby man. and 1 Crowcon Tetra 3 gas monitor per person in the duct/chamber. Two way radio (1 set per group)

WORK EQUIPMENT REQUIRED (continued) If the depth to bottom of the access shaft is more than 8ft (2.4m), all persons accessing the duct must be attached to the tripod when climbing in or out of the duct. The standby man must also be attached to the tripod. Refer to the procedure for use of the tripod. The tripod must be set up and in position BEFORE opening up any hatches.

EQUIPMENT ON STANDBY CLOSE TO THE WORK LOCATION (FOR THE RESCUE TEAM) Tripod Skedco Oregon Spine splint SKED Stretcher Two nylon webbing straps for the SKED Stretcher Neck brace One spare radio handset (minimum requirement) Three climber’s helmets Disposable boilersuits Three head torches Three harnesses Gas detector (at least one, preferably more) Knee pads Protective gloves, thermally rated gloves and sleeves (if likely to be in contact with exposed hot pipework) First Aid Kit

ITEMS NOT PERMITTED IN THE DUCT UNDER THIS PROCEDURE Adhesives, solvents, degreasants and paints Gas cylinders or equipment connected to gas cylinders (e.g. oxy-acetylene welding equipment, carbon dioxide fire extinguishers) Petrol/diesel fuelled equipment

THE WORK TEAM Minimum of 3 persons required for all operations in ducts. Minimum of two persons to carry out works in the ducts, no lone working permitted in the ducts. 1 man to remain outside at all times, this person should always stay at one of the access points. On no account should this person enter the duct.

THE RESCUE TEAM At least four people who have been trained (i.e. have attended one day training course) should be available. One of these can be the standby man already involved in the work, however none of those already in the duct can be included in this number. Supervisers should ensure that these people can be contacted for the duration that the duct/chamber will be accessed. At least one member of the rescue team should be a trained first aider. This person should be the first to enter the duct so that they can assess the casualty’s condition.

CHECKS PRIOR TO ENTERING THE DUCT The pre entry checklist should be completed. Checks of PPE and work equipment Check that radios and torches are fully charged. Check the tripod and winch if these are being used (note: the Procedure for use of the tripod provides details of the checks required). Ensure that the tripod legs are located on stable ground at least 300mm from the opening. Carry out pre-use check on harnesses (note: as per procedure for use of harnesses). Confirm that rescue equipment is available close to the work location.

Checks of PPE and work equipment (continued) Confirm that no gas cylinders or hoses, chemicals or solvents are being taken into duct. If there is a risk of burns in the duct (i.e. from unlagged heating pipework), confirm that the appropriate PPE is being worn (note: the Procedure for work on, or near, pipework which contains steam or hot liquids contains details of the PPE to be worn). Switch on and ‘zero’ the personal gas monitors in fresh air prior to entering the duct.

Checks of the work location Check that no works requiring a Permit to Work are being carried out in the duct. Wherever possible, at least two access chambers (either side of the work area and as close as practicable) should be opened along the duct to allow natural air movement and two directions of escape. Access to any ducts which only have one means of access/egress must be risk assessed on a case by case basis. Barrier off area around access chambers to ducts using barrier system. Check surface route of duct to ensure that no car engines or generators are running close to access or ventilation points, person of surface to monitor throughout period of the works. 

Checks of the work location (continued) Check for any signs of water on the duct floor. Use a torch for this if the lighting is poor. Check ladder tag on fixed ladders to confirm that the ladder has been inspected within the last 6 months. Visually inspect the ladder from the surface to check it is in good condition. Use a torch for this if the lighting is poor. Switch the Crowcon Tetra gas monitor on and ‘zero’ it in fresh air. Confirm that the duct is safe to enter by using the Crowcon Tetra gas monitor with the integral pump running and extension tubes attached. Lower the intake extension tube to the bottom of the shaft and leave for 2 minutes, then raise the intake tube to midway up the shaft and leave for 2 minutes. The discharge tube should be located away from the opening.

WORK IN DUCTS Minimum of two persons to enter the duct, these persons must remain in close proximity to each other. Personal gas monitors to be carried around by those in the ducts at all times whilst working in the ducts. Standby man to be in constant communication with those working inside the duct either by shouting or two way radio, contact must be made at least every 5 minutes. At the surface the standby man must also be attached to the fall arrest block attached to the eyelet at the top of the tripod. All other persons should be excluded from the area immediately next to the open hole. The standby man must leave the extension tube in place at the bottom of the access point and Crowcon Tetra gas detector with the pump running at the surface for the duration of the work.

EMERGENCY PROCEDURES In the event of a gas detector alarming: Evacuate the duct immediately Open up additional hatches, on no account should any University staff or contractors re-enter the duct. Contact supervisor The duct may only be re-entered if the gas detector gives the all clear once the extension tube is lowered into the area. In the event that the all clear is not given, a specialist contractor with expertise in entry to confined spaces using breathing apparatus must be contacted. In the event of injury or accident: Standby man to radio the Security Control Room and ask them to call the emergency services. Standby man to radio the superviser who will in turn mobilise the Rescue Team.

HOT WORKS IN UNDERGROUND DUCTS AND CHAMBERS Introduction This procedure provides information on the requirements when hot works are carried out in underground ducts and chambers. These are in addition to the general requirements for entering these areas. This procedure covers the use of arc welding and cutting equipment. Gas cylinders and associated hoses are NOT permitted in the ducts. In extreme circumstances where there is no alternative but to use such equipment this must risk assessed and approved by the Assistant Estates Director. 

Additional PPE required Long sleeved flame retardant boilersuit Welders gauntlets (person carrying out welding) Welders visor (both the person carrying out the welding and the person(s) assisting him)

Additional work equipment required AFFF extinguisher (taken into duct) Portable fans and ducting for supply and extract between access and egress points Generator for portable fans and arc welding equipment (if a power supply is not available)

Additional checks required prior to entry Ensure that a Hot Works Permit has been issued for the work. At least two access chambers must be opened along the duct to allow points for supply and extract ventilation to be located. Ensure that portable generators and the termination point of extract ductwork are located well away from access and ventilation points. Ensure portable fan units are located where they cannot be knocked over. 

Additional requirements for work in ducts Locate extract ductwork as close as possible to the welding area Fire watch to be maintained at end of the works, period as specified in the Hot Works Permit to Work.

DUCTS AND CHAMBERS WITH SPECIFIC RESTRICTIONS IN PLACE Duct between Kings Pavilion and Kings Pavilion Plantroom- staff must not enter this duct when ASV staff are dosing the swimming pool chemical system.