ower crane are commonly use and design for heavy lifting or transfer construction materials in easy ways just like rebar’s, pre cast, and other construction heavy materials needed.
Erection of tower crane is so easier said than done, it’s too risky than we think because one mistake equals to life of many people’s, its needs an expertise to do that specified work and technical knowledge of the equipment and most is experience on how erection of tower crane done. You have to familiarize all the details components of tower crane before start erection, and check all the components if it’s in good quality and makes it sure that it is certified pass undergo the standard procedure requirements, just testing of material, 3rd party certification and among of the above is safety first and help from the above all our Almighty God.
The following are the Methodology on how erection of tower crane prepare and done.
METHODOLOGY ERECTION OF TOWER CRANE
I. ERECTION SEQUENCES
This erection procedure allows a rapid assemble of the crane until it reaches its telescoping position.
It requires an auxiliary mobile crane, the characteristics of which much correspond to the parts to be handled.
Reducing the operating time of the auxiliary crane to the minimum on site involves a good coordination between the erection and assembling sequences, the erection team and the appropriate accesses and assembling area.
II. GENERAL INSTRUCTION FOR ERECTION
All the handling operations using the mobile crane must carried out safely.
Do not overload the mobile crane.
Use slings in good order and of correct lengths according to the weights of the parts to be lifted.
Pay attention to all the slinging points.
Make sure that all the necessary protection and safety means are fitted and used, such as ladder, platforms, guard-rails, safety belt etc.
It is absolutely forbidden to lift a load if the counter jib ballast weight is not fitted.
The crane must not be telescoped up with the wind speed exceeding 13 miles/sec.
It is essential that regulations on the number of the counter jib ballast weight subject to the jib lengths are observed strictly
III. PREPARATION OF CONCRETE BLOCK CRANE FOUNDATION
Preparation condition – The table of forces and stresses, the dimensional characteristics of the fixing angle, the fitting of fixing angles to determine a concrete blocks dimensions and reinforcement.
How to choose the concrete block – It is permissible ground pressure of the site that determines for the final height to be reached and for each type of machine, the best type of block to use for tower crane with any height, choose the block with a ground pressure equal to or lower than that of the ground site.
Dimensional characteristics of the fixing angle – The fixing angles must be fitted symmetrically in relation to the axes of the block and form a 2 meter square according to the dimension of the mast.
IV. ASSEMBLING THE PARTS OF THE CRANE
Assembling the 1.6 x 1.6 x 3m mast section - Fit and fix the mast section panel with 20 mast bolt and nut, 3m ladder and rest platform with guard rail.
Assembling the upper and lower slewing - Fit and fix the upper slewing into lower slewing. Fit and fix the 2 set slewing reducer with motor. Install the slewing platform and guard rail. Install the cabin platform and guard rail and fit and fix the operator’s cabin
Assembling the cat head ( Tower Head ) – Fit and fix the connecting plate, tie bar using shaft and split pin. Install ladder back to back using bracket.
Assembling the counter jib – Install the side platform and guard rail. Fit and fix the hoist winch motor and electric panel box. Assembling jib suspending beam for maintenance and service.
Assembling the jib – Prepare brackets with 1 meter height and 1.3 minimum wide. Place the jib assembly at the top and connect each one up to required length of boom using shafts and split pins then place the trolley to the jib and push it to the foot of jib No. 1. Connect the trolley motor with the trolley winch. Reeve the trolley rope and tighten it. Place the trolley at the root of the jib No. 1 and the front rope on the trolley winch should not less than 3 rounds. Install the service platform and guard rail for trolley winch service on the jib. Connect the tie bar according to the total length of the jib required.
V. ERECTION
Fixing angle - Fit and fix the fixing angle and tighten together with the embedded j-bolt and torque in accordance to the diameter of the shaft.
Base mast (Special Mast 1.5m) – Fit and connect to fixing angle with the 8 – 65mm diameter shaft pin with lock pins. Check the horizontal and vertical alignment.
Mast section 1.6x1.6x3m – Connect the mast section up to the required height using 55mm diameter shaft pin with lock pins.
Monoblock 1.6x1.6x3m – insert the monoblock according to sequence intended for internal climbing.
Slewing assembly – Fit and connects to the last mast section using 8-50mm diameter shaft pin with lock pins.
Tower head assembly – Fit and connect to the upper slewing.
Fitting the counter jib – Before slinging the counter jib, first lift the counter jib off the ground about 1meter and correct the slinging points for balance if necessary. Connect the counter jib to the cab mast by means of 90mm diameter shaft pins and lock pins.
Fitting the counter weight ballast – Fix one (1) concrete ballast according to sequence as counter balance before connecting the full length of jib assembly.
Fitting the Jib – Raise the jib from the ground and check its stability and horizontal level. Make the jib appreciably tilt. Sling and raise it until it reaches the pinning points, and connect it with the cat head. Pin connect the jib to the tower head and insert split pins to lock it.
Fitting the tie bars of the counter jib – Fit the tie bars of the counter jib after fitting of the tie bars of jib is over. Keeps the mobile crane slinging the jib at the same time without releasing. Pin-connect the tie bar already moved to the counter jib foot with the tie bar on the tower head using 60mm diameter shaft pin and lock pins.
Fitting the counter weight ballast – Fit the remaining counter weight ballast one by one according to the various length of the jib after the accomplishment of crane erection. Pin it by using 50mm diameter shafts. As soon as all the blocks are fitted, they must be locked together using the locking plate bar. Rope reeving for the hoist winch together with the lifting block.
VI. COMMISSIONING OF UNIT
Install all platform and safety rail.
Prepare power supply – 440 v, 60 Hz
Installation of riser cable.
Testing controls and motors.
Calibrations of all limit switches.
Load testing with the third party involved for certifying the unit.
Hand-over the unit with complete certificate ready for operation.
THE SAFETY RULES OF THE CRANE
I. The regulation of the correct used.
It is not to use crane until it finished the test.
According to the specified of the technology and the method of use, it must be the crane in its good condition, pay more attention to the safety to prevent the dangerous! To eliminating all kinds of malfunctions which could cause the safety accident immediately.
Operate the crane in the specified cope of temperatures.
Abide the specified in the instruction, examine, repair and maintenance.
II. Safety Measures.
Read and understand the operation and service manual rules before operation.
The operator should always remember all kinds of safety measures and recognize the fatalness and the operation rules should visible.
Forbid the crane operator to get long hair, wears the robe and wear the jewelry.
Crane operator should used to read the warning board about safety and dangerous.
Stop the operation and report immediately to the concern personnel if the crane encountered abnormalities.
Do not change or add any parts unless manufacture agreed.
Examine and repair, lubricate and debug the crane in accordance with the cycle that specified in the instruction manual.
The crane operator should be aware of the position of the fireproofing equipments and its usage.
III. The qualification of the personnel.
It must be qualified personnel to operate the tower crane.
Crane operator must be trained. Ability of operator, rigger, erector and maintenance persons should regulate definitely.
Crane operator should clear their responsibilities and make him know that he should reject all the orders which against the safety.
Experienced personnel must supervise at job site when the tower crane operating by trainees and learners.
Installation, adjustment and maintenance for electrical must be operating by capable electrician.
Adjustment and maintenance for traveling mechanism brake system and trolley system must be carried out by professional.
Installation, adjustment and maintenance for hydraulic system carried out only by professional.
IV. The safety rules during working stage.
Before each starting check the order from the work principal. Switch on, got rid of fill block, loosen the device or other fixing device ( wind power