Standard Interpretations - Table of Contents Standard Interpretations - Table of Contents
• Standard Number: 1910.37; 1910.37(b)(4); 1910.28; 1910.28(a)(18); 1917.45; 1917.45(g)(3)


OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov.


March 26, 1985

Mr. Michael J. Lacey
Principal Safety Engineer
State of Nevada - DOSH
Department of Industrial Relations
1370 South Curry Street
Carson City, NV 89710

Dear Mike:

There is not a construction standard for the use of cranes during high wind conditions. There is a standard in the new "Marine Terminal" standard paragraph 1917.45(g)(3) - (
Attachment 1). Note this standard is for rail mounted cranes. In our discussions during Cal/OSHA advisory meetings, the cranes on the docks usually follow the procedure set in the table 2-A (Attachment 2). The dock workers start getting concerned at 20-25 mph because in the Bay Area there are a lot of gusts, it is not steady winds. The two documents could be used as guidelines for construction cranes.

This is also what is used for scaffold requirements as incorporated into the construction standards, 1910.28(a)(18).

The requirement for exit signs is not the number of employees in an establishment, but the physical layout of the building.

The interpretation of [1910.37(b)(4)] is vital ["If the direction of travel to the exit or exit discharge is not immediately apparent, signs must be posted along the exit access indicating the direction of travel to the nearest exit and exit discharge. Additionally, the line-of-sight to an exit sign must clearly be visible at all times."] If you have a square room with windows and no partitions, an exit sign would not be needed.

The same floor space, made up of individually separate rooms, in a maze configuration, with no windows, illuminated exit signs may be required to allow employees a safe [exit route].

The important words are immediately visible. If the inspector gets "lost" you need exit signs. If the inspector can immediately find the exit, no exit sign would be required.

Sincerely,


JAMES R. GUENTHER
Regional Safety Engineer

Enclosures

[Corrected 2/6/2004]
Attachment 1

Source - Federal Register, Vol. 218 No. 129, 30918-9

(g) Rail-mounted cranes (excluding locomotive types). (1) For the purpose of this section, rail-mounted cranes include bridge cranes and portal cranes. (2) Rated load marking. The rated loads of bridge cranes shall be plainly marked on each side of the crane and in the cab. If there is more than one hoisting unit, each hoist shall have its rated load marked on it or on its load block. Marking shall be legible from the ground level. (3) Wind-indicating devices. (i) After October 3, 1983, each rail-mounted bridge and portal crane located outside of an enclosed structure shall be fitted with an operable wind-indicating device. (ii) The wind indicating device shall provide a visible or audible warning to alert the operator of high wind conditions. That warning shall be transmitted whenever the following circumstances are present:

(A) When wind velocity reaches the warning speed, not exceeding the crane manufacturer's recommendations; and (B) When wind velocity reaches the shutdown speed, not exceeding the crane manufacturer's recommendations, at which work is to be stopped and the crane secured.

(iii) Instructions. The employer shall post operating instructions for high wind conditions in the operator's cab of each crane. Operators shall be directed to comply with these instructions. The instructions shall include procedures for responding to high wind alerts and for any coordination necessary with other cranes. (4) Securing of cranes in high winds. (i) When the wind reaches the crane's warning speed:

(A) Gantry travel shall be stopped; and

(B) The crane shall be readied for shutdown. (ii) When the wind reaches the crane's shutdown speed:

(A) Any portion of the crane spanning or partially spanning a vessel shall be moved clear of the vessel if safe to do so; and (B) The crane shall be secured against travel, using all available means of securing.

(5) The employer shall monitor local weather conditions by subscribing to a weather service or using equally effective means. (6) Stops and bumpers. (i) The ends of all tracks shall be equipped with stops or bumpers. If a stop engages the tread of the wheel, it shall be of a height not less than the radius of the wheel. (ii) When more than one crane operates on the same runway or more than one trolley on the same bridge, each crane or trolley shall be equipped with bumpers or equivalent devices at adjacent ends subject to impact. (7) Employee exposure to crane movement. When employees may be in the vicinity of the tracks, crane trucks shall be equipped with personnel-deflecting guards. (8) Pedestrian clearance. If the track area is used for employee passage or for work, a minimum clearance of three feet (0.9 m) shall be provided between trucks or the structures of rail-mounted cranes and any other structure or obstruction. When the required clearance is not available on at least one side of the crane's trucks, the area shall not be used and shall be marked and identified. (9) Warning devices. Rail-mounted cranes shall be equipped with an effective travel warning device which shall be used to warn employees who may be in the path of the moving crane. (10) Communications. Means of communication shall be provided between the operator's cab and the base of the gantry of all rail-mounted cranes. This requirement may be met by telephone, radio, sound-signalling system or other effective methods, but not solely by hand-signalling.
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Attachment 2

Source: ACCIDENT PREVENTION MANUAL FOR INDUSTRIAL OPERATIONS,
8th Edition, National Safety Council, p. 43

Table 2-A

FORCE OF WIND FOR GIVEN VELOCITIES

Miles per hour (V) Feet per minute Feet per second Force in pounds per square foot (0.004V2) Description
1 88 1.47 0.004 Hardly perc.
2
3
176
264
2.93
4.40
0.014
0.036
Just perc.
4
5
352
440
5.87
7.33
0.064
0.1
Gentle breeze
10
15
880
1,320
14.67
22.0
0.4
0.9
Pleasant breeze
20
25
1,760
2,200
26.6
29.3
1.6
2.5
Brisk gale
30
35
2,640
3,080
44.0
51.3
3.6
4.9
High wind
40
45
3,520
3,960
58.6
66.0
6.4
8.1
Very high wind
50 4,400 73.3 10.0 Storm
60
70
5,280
6,160
88.0
102.7
14.4
19.6
Great storm
80
100
7,040
8,800
117.3
146.6
25.6
40.0
Hurricane
-From Kidder-Parker, Architects and Builders Handbook.
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March 21,1985

Mr. James R. Gunther
Regional Safety Engineer
USDOL/OSHA
450 Golden Gate Ave.
San Francisco, CA 94102

Dear Jim:

The question concerning wind conditions closing down the job on cranes, etc., in the construction of high-rise buildings has been presented to us recently.

Do you know of any standards or interpretations concerning this subject? I would appreciate your expertise in this matter. Also, Jim, with regards to 1910.37(q) are there any deviations from this standard that you know about? For example, if a small company (10 or fewer employees) trains its employees as to the locations of exits, may they then disregard the need for exit marking?

Jim, thanks for your past efforts in aiding us with our interpretations. I look forward to hearing from you regarding these questions.

Sincerely,



Michael J. Lacey
Principal Safety Engineer



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