Conventional cargo gear mechanics

Spot the midships (up-and-down) boom as close to the fore-and-aft centerline of the hatch as operationally possible so the guys and preventers lead effectively and safely support lateral stresses. This is the recommended practice in Appendix III to Part 1918 because centering the up-and-down boom gives the best geometry for the guys and preventers to resist lateral loads when married falls are used. See Appendix III to Part 1918 and the rigging/operating provisions in 1918.52, 1918.53, and 1918.54.

You should avoid leads that are nearly vertical because as the lead approaches vertical the total stress in the guy or preventer increases rapidly, which raises vertical loads transmitted into the boom and topping lift and can create hazardous compressive and tensile stresses. Appendix III explains that a near-vertical lead greatly increases the vertical component of the force required to resist lateral loads, putting heavy compressive stress on the boom and heavy tensile stress on the topping lift and increasing the risk of boom failure or jackknifing. See Appendix III to Part 1918 and the related rigging rules in 1918.52–.54.

Yes — preventers should run as closely parallel to the guys they support, and they must not be attached to the same fitting. Appendix III explicitly advises that preventers, when used, should parallel the guys as closely as possible so they share loads correctly, and it warns that guys and preventers must not be secured to the same fitting because that can defeat the independent backup function of the preventer. See Appendix III to Part 1918 and the rigging/operating standards in 1918.52–.54.

You must prevent cargo falls and runners from chafing on any standing or other running gear while under load by arranging gear so running rigging moves freely and by keeping contact points smooth and clear. Appendix III states that while under load the cargo falls (running rigging) must not be allowed to chafe on standing or other running gear, cargo runners must work freely through the heel block without chafing the cheek of the block, and bobbing chains and heel block preventers must be attached so they do not interfere with runner movement. Regular inspections and immediate correction of pinch or rubbing points (e.g., worn sheave cheek, frayed rope contact) are practical controls. See Appendix III to Part 1918 and the related equipment operation provisions in 1918.52–.54.

When guys approach the vertical, the topping lifts take increased tensile load and the booms carry increased compressive load; this matters because those stresses can overload components and lead to structural failure. Appendix III explains that the vertical forces generated as the leads approach vertical are transmitted substantially to the boom and topping lift, producing proportionate compressive stresses in the boom and tension in the topping lift—so rigging and components must be capable of handling those loads and rigging angles should be chosen to avoid excessive stresses. See Appendix III to Part 1918 and the rigging rules in 1918.52–.54.

To reduce jackknifing risk, place guys and preventers so they develop enough vertical resistance, spot the boom close to the hatch centerline, and ensure preventers run parallel to the guys and are independently attached. Appendix III states that adequate vertical resistance from properly placed guys and preventers is necessary to prohibit the boom from jackknifing while cargo moves across the deck; proper spotting and separate fittings for guys and preventers are emphasized. See Appendix III to Part 1918 and related rigging/operating requirements in 1918.52–.54.

Attach bobbing chains and heel block preventers so they are clear of the cargo runner path and do not block or rub against the runner or the cheek of the heel block. Appendix III instructs that bobbing chains and heel block preventers must be attached in a manner that does not interfere with the movement of cargo runners and that runners must pass freely through the heel block without chafing the cheek. Practical steps include routing attachments away from sheave paths, using proper hardware and rigging points, and testing runner movement before lifting. See Appendix III to Part 1918 and the relevant rigging sections 1918.52–.54.

No — while under load, cargo falls must not be permitted to chafe on any standing or other running gear. Appendix III explicitly states that during lifting operations the running rigging must be kept from chafing on other gear, and the general rigging and operation standards in 1918.52–.54 set expectations for safe rigging and handling. Regular inspection and maintenance of sheaves, blocks, and lines will help prevent chafing-related failures. See Appendix III to Part 1918.

Special care requires placing guys and preventers so they develop adequate vertical resistance, run nearly parallel to each other, and are attached to separate fittings so each can do its job independently. Appendix III warns that Burton and yard booms need particular attention to preventers and guys because of the married-falls geometry; preventers should closely parallel the guys and must not share the same fitting, and overall spotting should keep the up-and-down boom near the hatch centerline. See Appendix III to Part 1918 and the guidance in 1918.52–.54.

Before lifting, check that the cargo runners pass freely through the heel block without rubbing the cheek, that sheaves are free and well-greased, and that bobbing chains or preventers are not obstructing the runner path. Appendix III emphasizes that cargo runners must work freely through the heel block and must not chafe the cheek, and that attachments like bobbing chains and heel block preventers be located so they do not interfere with movement. Perform a manual pull test and visual inspection before taking a load. See Appendix III to Part 1918 and 1918.52–.54.

Whether a latch is required depends on the application, but crane hooks in longshoring must be latched or otherwise secured to prevent accidental load disengagement, and cargo bridles that remain attached must be secured by shackle or other positive means. OSHA's 2006 letter explains that the slings standard (1910.184) does not categorically require latches on every sling hook, but maritime and longshoring rules (for example, 1918.66(e)(2) and 1918.81(b) as discussed in that letter) require crane hooks be latched or otherwise secured and that bridles left on hoisting gear be attached by shackles or other positive means. Use latch-equipped hooks where practical and follow the specific longshoring provisions cited in the letter. See the OSHA interpretation "Safety latches on sling hooks" (2006) and Appendix III to Part 1918 / 1918 requirements.

No — a crane operator may not leave the controls while a load is suspended; the employer must ensure the assigned operator can complete the lift without unscheduled interruption. OSHA's 2013 interpretation makes clear that if an operator becomes incapacitated and must abandon the controls while a load is suspended, the employer is not maintaining a safe operation and may be cited; this expectation applies to lifting operations covered by 1918. Employers should assign physically capable operators and have contingency plans so loads are never left unattended. See the OSHA letter "Crane operator medical condition scenario" (2013) and 1918 requirements.

As the guy's lead angle becomes more vertical, the vertical component of the guy's tension must increase sharply to resist lateral forces, so the total tension in the guy rises rapidly. Appendix III describes that when a guy approaches the vertical while supporting the boom head, the vertical force needed to counteract any horizontal force gets larger, which increases the total stress in the guy and transfers more compressive force into the boom and more tension into the topping lift. For safe rigging, maintain lead angles that keep guys effective without creating excessive vertical loads. See Appendix III to Part 1918 and the rigging sections in 1918.52–.54.

Before lifting, spot the up-and-down boom near the hatch centerline, verify guys and preventers are placed and attached independently and run parallel, ensure topping lifts and booms are fit for the expected compressive/tensile loads, and confirm cargo falls and runners run freely through blocks without chafing. Appendix III provides these non-mandatory but practical checks for conventional gear; combine them with the mandatory rigging and operating rules in 1918.52–.54 to form a pre-lift checklist. Document any remedial actions and do a trial pull if needed. See Appendix III to Part 1918 and 1918.52–.54.