3.2 Shafts, belts, sprockets and the 60-day rule

1 The seven-foot line

1910.219 repeats one dimension over and over, and once you have it, half the standard is predictable. Seven feet above the floor or working platform is the height at which guarding stops being required, on the theory that a person cannot reach it. Below seven feet, it is guarded.

• (b)(1) Flywheels located so that any part is seven feet or less above floor or platform shall be guarded.
• (c)(2)(i) Horizontal shafting. All exposed parts of horizontal shafting seven feet or less from floor or working platform, "excepting runways used exclusively for oiling, or running adjustments," shall be protected by a stationary casing enclosing the shafting completely, or by a trough enclosing sides and top or sides and bottom as the location requires.
• (c)(3) Vertical and inclined shafting seven feet or less from floor or working platform, "excepting maintenance runways," shall be enclosed with a stationary casing.
• (d)(1) Pulleys, any parts of which are seven feet or less from the floor or working platform, shall be guarded.
• (k)(1) Clutches, cutoff couplings and clutch pulleys with projecting parts, located seven feet or less above the floor or working platform, shall be enclosed by a stationary guard. A "U" type guard is permissible.

The two exceptions in (c) are the interesting part for this trade: oiling runways and maintenance runways are carved out of the guarding requirement, because the whole point of them is access. That access is bought with a different protection — (c)(5)(v) requires that "the route followed by the oiler is protected in such manner as to prevent accident," and (c)(5)(i) requires the transmission room to be "locked against unauthorized entrance."

2 The small projections that take hands and sleeves

Two paragraphs cover the details that maintenance work creates and then leaves behind. 1910.219(h)(1): "All projecting keys, setscrews, and other projections in revolving parts shall be removed or made flush or guarded by metal cover." There is an exception for keys or setscrews inside gear or sprocket casings, and for keys, setscrews or oil cups in hubs of pulleys under twenty inches in diameter where they are within the plane of the rim.

A projecting setscrew on a rotating collar is invisible while it spins and catches a sleeve at any speed. Every coupling you reassemble, every sprocket you re-key, every collar you set is an opportunity to leave one sticking out.

1910.219(c)(4)(ii) is even shorter: "Unused keyways shall be filled up or covered." And (c)(4)(i) requires projecting shaft ends to present a smooth edge and end, and not to project more than half the diameter of the shaft unless guarded by nonrotating caps or safety sleeves. (i)(1) requires revolving collars, including split collars, to be cylindrical, with screws or bolts that do not project beyond the largest periphery of the collar; (i)(2) requires shaft couplings to be constructed to present no hazard from bolts, nuts, setscrews or revolving surfaces, allowing bolts and setscrews only where covered with safety sleeves, or used parallel with the shafting and countersunk or not extending beyond the coupling flange.

3 Belts, gears, sprockets and chains

(f)(1) gives two ways to guard gears — "by a complete enclosure" or by the other methods listed in that paragraph — and the belt rules in (e) are dimensional. Where both runs of a horizontal belt are seven feet or less from the floor, the guard shall extend at least fifteen inches above the belt or to a standard height; and where both runs are 42 inches or less from the floor, "the belt shall be fully enclosed."

Overhead horizontal belts get their own three triggers in (e): a guard is required if the belt is located over passageways or work places and travels 1,800 feet or more per minute, if the center-to-center distance between pulleys is ten feet or more, or if the belt is eight inches or more in width. Any one of the three.

Two more that show up in real plants. (l)(4): belts that must be shifted by hand, and belts within seven feet of the floor or working platform that are not guarded, "shall not be fastened with metal in any case, nor with any other fastening which by construction or wear will constitute an accident hazard." (l)(2) is a recommendation rather than a requirement and worth knowing anyway: "The use of belt poles as substitutes for mechanical shifters is not recommended."

4 Paragraph (p): the maintenance paragraph

Everything above is about hardware. 1910.219(p) is about the trade, and it is the only place in Subpart O that sets a general inspection interval.

Sixty days is a real number and almost nobody knows it. It is not a suggestion, it does not depend on criticality, and it applies to "all power-transmission equipment." A PM program that inspects drives annually is out of compliance with a paragraph that has been in force since 1974.

(p)(7) is the most quietly important sentence in the standard for personal safety. "Machinery shall be oiled when not in motion, wherever possible" is a lubrication rule with a hazardous energy rule inside it, and "wherever possible" is the employer's burden to fail, not yours to assume. And tight-fitting clothing is the standard admitting what actually catches: a sleeve, a cuff, a hood string, a badge lanyard.

5 Guard construction, when you are the one building it

Maintenance departments fabricate guards, and 1910.219 has opinions. (m)(1)(i) lists the acceptable materials for standard guards: "Expanded metal, perforated or solid sheet metal, wire mesh on a frame of angle iron, or iron pipe securely fastened to floor or to frame of machine." (o)(1) covers dimensions, and one requirement in it is easy to miss and easy to get wrong: "All guards shall be rigidly braced every three (3) feet or fractional part of their height to some fixed part of machinery or building structure. Where guard is exposed to contact with moving equipment additional strength may be necessary."

Bracing every three feet of height, to something fixed. A panel of expanded metal bolted at the corners and flexing in the middle does not satisfy it, and flexing is exactly how a guard ends up in contact with the thing it is guarding.

6 How to use 1910.219 in a PM program

The practical value of this standard is that it converts into a route. Once every sixty days, somebody walks the drives with the paragraph in hand and looks at seven things — and every one of them is a reliability item as well as a safety item, which is why this is the easiest safety inspection in the plant to get funded.

1. 1
   Guards: present, fastened, braced every three feet of height, no gap that admits a hand, no sharp edge on the guard itself.
2. 2
   Shafting: aligned, free of rust and excess oil, no projecting keys or setscrews, unused keyways filled, shaft ends smooth and within half a diameter.
3. 3
   Bearings and hangers: aligned and adjusted, and every supporting bolt and screw tight — (p)(3) and (p)(4).
4. 4
   Pulleys: aligned so belts do not run off; belts, lacings and fasteners inspected and in good repair, with no metal fastening on a hand-shifted or unguarded belt.
5. 5
   Couplings and collars: cylindrical, nothing projecting beyond the periphery, no exposed bolt heads on a rotating flange.
6. 6
   Lubrication points: reachable with the machine stopped. Any grease point that can only be reached while running is a PM defect and a redesign, not a technique.