ASME B30.6:2020 pdf download

ASME B30.6:2020 pdf download.Derricks
Volume B30.6 includes provisions that apply to the construction, installation, operation, inspection, testing, and maintenance of guy, stiffleg, basket, breast, gin pole, Chicago boom, shearleg, and A-frame derricks. These derricks, powered by winches through systems of wire rope reeving, are used for lifting, lowering, and horizontal movement of freely suspended unguided loads. Derricks are usually stationary mounted and may be temporarily or permanently installed. The provi- sions included in this Volume also apply to any variations ofthesetypesofderrickswiththesamefundamentalchar- acteristics, except those specified for floating derricks in ASME B30.8, Floating Cranes and Floating Derricks.
Aderrickis an apparatus consistingofa mastorequiva- lent member held at the end by guys or braces, with or without a boom, for use with a winching mechanism and operating ropes. A-frame derrick: a derrick in which the boom is hinged from a cross member or pedestal between the bottom ends of two upright members spread apart at the lower ends and joined at the top, the boom point is secured to the junction of the side members, and the side members are braced or guyed from this junction point (see Figure 6-0.2.1-1). basket derrick: a derrick without a boom, similar to a gin pole, with its base supported by ropes attached to corner posts orotherparts ofthe structure. The base is ata lower elevation than its supports. The location of the base of a basketderrickcan be changed byvaryingthe length ofthe rope supports. The top ofthe pole is secured with multiple reeved guys to position the top ofthe pole to the desired location by varying the length ofthe upper guy lines. The load is lifted and lowered by ropes through a sheave or blocksecured to the top ofthe pole (see Figure 6-0.2.1-2). breastderrick:aderrickwithoutaboom.Themastconsists oftwo side members spread fartherapartatthe base than atthe top, and tied together atthe top and bottom byrigid members. The mastis prevented from tipping forward by guys connected to its top. The load is lifted and lowered by ropes through a sheave or block secured to the top ofthe crosspiece (see Figure 6-0.2.1-3). Chicago boom derrick: a boom that is attached to a struc- ture, an outside upright member of the host structure serving as the mast, and the boom being mounted in a pivoting seat secured to the upright. The derrick is complete with load, boom, and boom point swing line falls (see Figure 6-0.2.1-4). gin pole derrick: a derrick without a boom that has guys arranged from the mast top to permit leaning the mast in one or more directions. The load is lifted and lowered by ropes reeved through sheaves or blocks at the top of the mast and the lower block (see Figure 6-0.2.1-5). guyderrick: a fixed derrickconsisting ofa mastcapable of being rotated 360 deg, but not continuous rotation, supported in a vertical position by guys, and a boom, the bottom end of which is hinged or pivoted to move in a vertical plane with a reeved rope between the head of the mast and the boom harness for lifting and lowering the boom, and a reeved rope from the boom point for lifting and lowering the load (see Figure 6-0.2.1-6). shearleg derrick: a derrick with a boom suspended from a mast or A-frame, not capable of swinging, hinged at the bottom and raised and lowered bya hoistmechanism or a hydraulic cylinder (see Figure 6-0.2.1-7). stiffleg derrick: a derrick similar to a guy derrick, except thatthe mastis supported or held in place bytwo or more stiff members, called stifflegs, which are capable of resisting either tensile or compressive forces. Sills are generally provided to connect the lower ends ofthe stiff- legs to the foot of the mast (see Figure 6-0.2.1-8).