Job: Dock Gantry Operator Description: Operates the Dock Gantry Equipment Assessed: VanTerm Dock Gantry ESSETIAL DUTIES 1. Operating the Dock Gantry A) Sitting B) Handling Controls C) Operating Foot Pedals 2. Ascending and Descending the Gantry on Essential Duties: Keep inside of the gantry cab clean Clean gantry cab windows if not done adequately by maintenance Shift Schedule: Two operators are assigned to each gantry per 8hr shift. Each operator works 4hrs and it is up to the operators to determine whether that is 2hrs on / 2hrs off or 4hrs on /4 hrs off. There are no coffee breaks with this job. Staffing: Two operators are assigned to each gantry every shift but they work alone in the crane. DESCRIPTIO OF ESSETIAL DUTIES 1. OPERATIG THE DOCK GATRY Frequency Operates the dock gantry crane for 4 hrs out of an 8-hour shift. Equipment Various dock gantry cranes Task Description Operator uses the gantry crane to load or unload containers between ships and bomb carts. Occasionally containers are unloaded from ship to the dock if there is a problem with the container or bomb cart, but this is a rare situation. On average 26-28 containers are loaded or unloaded by each operator per hour. This may be as high as 30 containers per hour on a very busy shift. Cycle time is approximately 2 mins per container, which includes positioning the head, locking on, lifting, moving the container, lowering, and releasing the container. Significant attention to detail is required and stress levels may be high in this job. ErgoRisk 2008 Page 1 of 7
A SITTIG Equipment Dock Gantry Crane Seat Duration up to 4 hours Frequency sustained Force n/a Task Overview Frequent and sustained neck and back flexion when hunching forwards to look down through the gantry floor windows to see the work. Frequent rotation of the neck to the left or right when gantrying or moving containers laterally. The operator is seated for the duration of the operating task. Frequent bending of the torso and neck up and down to see position of container as it is being moved. atural seated posture is typically a rounded upper back and forward head posture. Whole-body vibration when gantry is in operation. Significant jolt as gantry moves forward or backward out on the boom, especially if carrying a container. B HADLIG COTROLS Equipment Joysticks, switches, button controls Duration up to 4 hours Frequency Constant when operating Force minimal Task Overview The gantry operator s seat has a right arm console for hoist controls and a left arm console for trolley controls. Each console has a joystick, various button and switch controls. There is also a wall control panel with less frequently used controls, such as for lights, etc. Various different grips including power grip, pinch grip and modified pinch grips are required to handle the controls Operators must lean and twist the torso and reach backwards with an outstretched arm and shoulder to access the wall console. When handling the joysticks and leaning forward to view the operation, the operator s shoulders are typically in an extended position. Additional shoulder extension is required when operators reach further back to access other controls located behind the joystick. Complex small wrist movements in all directions may be required to manipulate the different controls. There are significant dexterity requirements to make fine adjustments to the crane. The arms are typically unsupported during all these control movements. C OPERATIG FOOT PEDAL Equipment Radio Pedal Duration up to 4 hours Frequency Intermittent when operating Force minimal Task Overview There is a single foot pedal on the floor of the crane cab to operate the radio. Operating the foot pedal requires ankle flexion and extension. The pedal is operated by the right foot and the operator depresses it to open the radio channel to speak to the tower checker. The foot pedal can be repositioned by moving it from bar to bar on the foot window frame. ErgoRisk 2008 Page 2 of 7
FUCTIOAL DEMADS with MSI POTETIAL Operating the Dock Gantry eck Static neck flexion, rounded upper back and forward head posture when looking down at the work can stress the structures in the neck and upper back. eck rotation in the horizontal plane to watch the load being moved laterally or twisting to control panel puts rotational stress on the structures in the neck. Back Lumbar spine rounds when sitting which places increased stress on the discs and other spinal tissues. Increased C-curve with unsupported forward leaning postures place increased mechanical stress on the back. Static use of back muscles from sitting for extended periods can increase fatigue. Twisting or side bending postures to access control panel or when viewing to the side can stress spinal tissues. When gantry moves out onto the boom there is a jolt that can add an additional impact stress to the spine. Shoulder Static shoulder extension when operating joystick controls while leaning forward can stress the shoulder joint Sideways reaching with an unsupported right arm to access control panel. Awkward arm and shoulder movements are required to access controls that are behind the seated operator at the rear of the consoles. Elbow/Wrist/Hand Complex small wrist movements are required in all directions to operate the joystick controls. Repetitive pinch grip is required for some knobs and switches. on-neutral wrist and forearm postures are required to access controls that are behind the seated operator at the rear of the consoles. Repetitive thumb and finger movements are required to push buttons and manipulate joystick for small movements. Static small finger extension is required to stabilize the hand for fine tuning movements with the joystick. STRATEGIES TO MIIMIZE MSI Operating the Dock Gantry eck Stretch the neck muscles often to allow tissue recovery resulting from awkward postures. Try tucking the chin to place the neck in proper alignment with the spinal column and then rotate the head to one side or the other. Hold the stretch for 20 seconds. When not required to view the load return neck to a neutral position and look straight ahead until required to look down again. File photos ErgoRisk 2008 Page 3 of 7
Back As much as possible, avoid sitting for extended periods of time to minimize static use of back muscles. Stand and stretch whenever waiting for bomb carts or during other breaks from activity. Take the opportunity to stretch or walk during scheduled breaks to restore blood flow to the spinal tissues. Minimize awkward sitting posture by taking the time to adjust seat for best fit. Reverse forward leaning postures by arching the back, squeezing the shoulder blades together and sticking the chest out (see picture at right). Shoulders Take hands off the joystick whenever not operating the controls. Let shoulders relax and hands rest in lap until required to reach back for joystick again. Sit as far back in the seat as possible to reduce the distance needed to reach behind to access the controls Elbow/Wrist Maintain neutral wrist posture when operating joystick and controls. Where possible use a power grip on the joystick to reduce stresses to the small structures in the hand. Keep wrist straight when reaching behind for other controls Let go of the joystick whenever possible to reduce static grip stresses to the elbow, hand and forearm. Perform wrist and forearm stretches with elbow straight to stretch muscles and increase blood flow after periods of particularly repetitive or prolonged static wrist and hand postures. 2. ASCEDIG AD DESCEDIG THE DOCK GATRY Frequency Once or twice per shift depending on whether the operators are working 4hrs on/4 off or working 2hrs on/ 2 hrs off. Occasional requirement to ascend out onto the trolley if the operator wants to check the condition of cables and shivs. This equipment is maintained by maintenance but may also be checked by operators once a week or less. Equipment one Task Description Operators climb a flight of stairs to access the gantry elevator. Once inside the elevator they close the sliding door and push a button to raise or lower the elevator. To get from the elevator to the crane cab operators walk along a catwalk and then open the door to the crane. The door pulls open when entering from the outside and pushes open when exiting from inside. A measured force of 40lbs was required to open the door on one 140ft dock gantry. OTE: The #2 gantry at the Fraser Surrey Docks is not equipped with an elevator and operators must climb stairs to a height of 60ft to access the gantry cab. ErgoRisk 2008 Page 4 of 7
Periodically the operator may also need to check the condition of the shivs and cables so he may climb a ladder up to the trolley catwalk above the cab. He then walks along the catwalk to perform a visual inspection. This task is performed once a week or less. ASCEDIG & DESCEDIG THE GATRY Equipment one Duration 1-2 minutes Frequency 1-2 times/shift Force Moderate (only to open door) FUCTIOAL DEMADS WITH MSI POTETIAL Ascending & Descending the Dock Gantry eck Significant neck flexion may occur as the operator looks down to ensure his footing when descending the stairs. Shoulder Significant pull/push force is required to open the door of the gantry. This can stress structures in the shoulder and arm. Knee Supporting body weight against the force of gravity when ascending and descending stairs can put stress on the structures around the knee. STRATEGIES TO MIIMIZE MSI Ascending & Descending the Dock Gantry eck Avoid sustained neck flexion when ascending or descending the stairs. Check footing then return to looking in front when climbing up/down. Shoulder Maintain a neutral shoulder posture with arm close to side of body when opening the gantry cab door. Use body weight to assist in open close rather than just pushing or pulling with the arm. Knee Use hand rail to help with balance and to assist in pulling up body weight when ascending or to slow rate of descent when coming down the stairs. 3. EVIROMETAL COSIDERATIOS Exposure to Elements The operator is inside the gantry cab for the duration of the time he is operating the gantry. He/she is exposed to the elements when ascending/descending the stairs to the elevator and when walking along the catwalk between the elevator and the gantry cab. Uneven Surfaces ot applicable to operator s role in the operation of machine. ErgoRisk 2008 Page 5 of 7
Vibration The operator is exposed to whole body vibration throughout operation of the gantry crane. There is also sway in the cab if the container is swinging on the hoist and there are significant bumps and jolts as the crane is moving, particularly when the gantry cab moves out on the trolley and crosses a split in the rail. This force of this jolt is increased if the crane is moving a container. ErgoRisk 2008 Page 6 of 7
4. PHYSICAL DEMADS SUMMARY TABLE Job Demands Max. Weight/ Avg. Weight (Kg)m Duration per exposure h=hrs s=secs, m=mins Frequency Comments OTE: On average 26-28 containers are moved per hr, with a container being lifted, moved, lowered and released approximately every 2 minutes. STREGTH POSTURE & MOBILITY EVIROMET Lifting/Carry Push/Pull 18/3.5 <10s F Complex small movements of joystick forward and back, and gross mvt to open/close cab door Supporting Body Weight 1min R Ascending/Descending gantry 2-4 times/shift Gripping / Handling <1m F Joysticks and other controls Fine Motor Skills <10s F Complex small movements of joystick control to complete each container transfer Sitting 4hr F Constant sitting for duration of work Driving Standing <15s R Stand & bend to adjust seat before starting work, brief standing if checking something on boom. Walking < 1m R Along catwalk to get to/from cab (<30s) or if need to check something on the trolley. Bending/ Stooping 4h F Sitting bent forward to view work through window in floor of cab Sustained Crouching/ Kneeling Climbing Stairs <30s R 1 flight to/from elevator (< 30 secs) during usual duties or max 15 mins to ascend/descend from cab if elevator out of service extremely rare Climbing Ladders R To upper trolley catwalk to check shivs and cables Crawling Balancing R On ladder up to trolley catwalk Throwing Overhead Reach <5s R Adjusting mirrors inside cab Exposure to Elements <1m R When ascending/descending stairs or when on catwalk Uneven Surfaces Proximity to moving objects Vibration (upper extremity) Vibration (whole body) F Constant low level vibration when operating gantry Frequency Ratings: : ever R: Rare - ot daily or up to 1% of shift (<5mins/day) O: Occasional - 1%-33% of shift (up to 2.5hrs) F: Frequent - 34%-67% of shift (2.5-5hrs) C: Constant ->67% of shift (>5hrs) ErgoRisk 2008 Page 7 of 7