Hoisting drum

Normally, a hoisting system has an even number of working lines between the traveling block and the crown block. The fast line is spooled onto the drawworks hoisting drum. The dead line is anchored to the rig floor across from the drawworks. The weight indicator is a load cell incorporated in the dead line anchor. 

The drawworks basically contains the hoist drum, the transmissions, the brake systems, the clutch systems, rotary drive sprocket, and cathead. Figure 4-10 shows a schematic of the drawworks. 

In Figure 4-11, the driller s console is at the left of the drawworks. Also, the hoisting drum and sand reel can be seen. The driller s brake control is between the driller s console and the drawworks to control the brake systems of the hoisting drum. 

Often it is necessary to calculate the line-carrying capacity of the hoist drum. The capacity or length of drilling line in the first layer on the hoist drum L, (ft) is... 

The total length of drilling line on the hoisting drum, (ft), will be the sum of all the layers ... 

A hoist drum has an inside length of 48 in. and an outside diameter of 30 in. The outside diameter of the flange is 40 in. The drilling line diameter is 1 in. Find the total line capacity of the drum. The flange length is... 

Traveling blocks A heavy duty pulley system that hangs in the derrick and travels up and down with the hoisted tools. It is connected to the crown block with a wire rope that ultimately runs to the hoisting drum. 

Alternatively the fleeting angles of the ropes coming off the drum could be thrusting the hoist drums outboard resulting in a reduction in the air gaps of the brake units in operation. 

The discs on the Ventilation Shaft Kibble Hoist drum hoist required quite extensive maintenance. This could be a combination of contamination, incorrect grade of disc material or certain inclusions in the pad material. Nevertheless, the discs do require grinding at regular... 

Correlation between predictions and measurements was relatively poor with the first method. However, its simplicity makes it a suitable tool for demonstrating the effect of head rope torque on the slip behaviour at the hoist drum and the associated influence on friction work. Yiassoumis (1992) used a four-rope Koepe hoist at the West Driefontein Mine in South Africa in his study. The parameters of the 44 mm non-spin rope employed on the hoist are shown in Table 1. For comparison purposes, parameters of a Haggie triangular strand rope of the same diameter are also shown. Essential parameters of the West Driefontein Hoist are shown in Table 2. 

The cyclic load limitation for synthetic ropes in the Koepe hoist application is unknown and would require testing to determine an appropriate limit. However, it is known based on existing fatigue life data that high performance synthetic materials have better life compared with steel. Moreover, service life of Koepe hoist ropes is essentially a Bend-Over-Sheave (BOS) and tension-tension fatigue relationship, which are well-known and studied phenomena that are relatively easily simulated and tested, as opposed to drum hoist ropes for which rope life is primarily limited by rope-to-rope interactions on the hoist drum which is difficult to model, test and predict. 

Ensuring adequate friction between the ropes and hoist drum is the basic premise of a Koepe hoist. The main factors include ... 

Angle of wrap of rope around the hoist drum (0)... 

Increasing the angle of wrap around the hoist drum by using deflection sheaves. An increase from 180 to 210 increases the maximum allowable T1/T2 to greater than the required actual T1/T2 for the synthetic-roped Koepe. This may not be practical,... 

A greater distance from the skip dumping position to the hoist drum reduces the effects of hoist drum groove differentials. This may favor a ground-mounted Koepe which has a very long length from hoist drum to skip dump position. 

Double-wrapped hoist drum/sheave configuration to provide a high level of friction, allowing T1/T2 ratios of up to 2.7... 

Headlf ame height would be greater (for a tower-mounted Koepe) to allow adequate distance between the sheave and hoist drum. The additional distance is roughly 30% greater than that required for a BMR hoist. 

Determine applicabihty of synthetic rope for conventional hoist drum design... 

Mid height of the catenary means half the vertical distance between the hoist drum and the head sheave. 

The head ropes in the friction hoist configuration pass over the drum and are driven by friction between the rope and the drum lagging. Friction hoist drums are typically fitted with multiple head ropes. Friction hoist skips are fitted with tail ropes to maintain the rope tension... 

The head ropes in a drum hoist configuration are terminated to the hoist drum and coil onto the drum as the associated skip is raised and off the drum as the skip is lowered. Drum hoists are configured with one or two head ropes on each skip. Drum hoist skips typically have... 

The rock hoist drum shaft assembly comprise of an overlay drumshaft coupled to an imderlay drumshaft via a Hooke s joint, each shaft weighing 61,000 kg and Hooke s joint 26,000 kg. The shafts are manufactured from vacuum degassed forged steel, normalized and machined all over. 

Controlled load lowering means lowering a load by means of a mechanical hoist drum device that allows a hoisted load to be lowered with maximum control using the gear train or hydraulic components of the hoist mechanism. Controlled load lowering requires the use of the hoist drive motor, rather than the load hoist brake, to lower the load. 

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