OSHRC Docket No. 83-1262


Before:  BUCKLEY, Chairman; WALL, Commissioner.


This case is before the Occupational Safety and Health Review Commission under 29 U.S.C. 661(j), section 12(j) of the Occupational Safety and Health Act of 1970, 29 U.S.C. 651-678 ("the Act").  The Commission is an adjudicatory agency, independent of the Department of Labor and the Occupational Safety and Health Administration ("OSHA").  It was established to resolve disputes arising out of enforcement actions brought by the Secretary of Labor under the Act and has no regulatory functions.  See section 10(c) of the Act, 29 U.S.C. 659(c).

Towne Construction Company is a Canton, Ohio, general construction contractor.  In 1983 Towne held a subcontract to construct a water reservoir at Timken Steel's new Faircrest Steel plant in Canton.  On September 27, 1983, it was in the process of tying reinforcing steel ("rebars") into mats, which would be installed in the walls of the reservoir before concrete was poured.  A 25-ton
Grove truck crane was used to lift the mat from its horizontal position to a nearly vertical position, where it would be tied off and then put into the wall by a smaller crane.  When one end of the mat was nearly vertical to the floor, the boom of the crane collapsed, causing the steel mat to strike and kill one of Towne's employees who was on the floor assisting in the positioning of the mat.

The Secretary of Labor issued citations to Towne alleging violations of two crane safety standards.  Administrative Law Judge James D. Burroughs affirmed both citations.  We affirm one citation and vacate the other.

Citation 1:  29 C.F.R. 1926.550(a)(1), Exceeding Crane Manufacturer's Load Limitations

In citation 1 the Secretary alleged that, contrary to 29 C.F.R. 1926.550(a)(1), the angle of the crane's boom was less than that required by the crane manufacturer's load limitations chart to lift a load of the weight involved here.  The standard provides:
1926.550 Cranes and derricks.

(a) General requirements.  (1) The employer shall comply with the manufacturer's specifications and limitations applicable to the operation of any and all cranes and derricks. . . .

Delegation Issue
Towne argues that the first sentence of section 1926.550(a)(1) constitutes an invalid delegation to crane manufacturers by the Secretary of the legislative authority that Congress granted exclusively to the Secretary.[[1]]  Towne points out that the first sentence of the standard requires an employer to comply with specifications and limitations set by crane manufacturers, not by the Secretary.  Judge Burroughs concluded that Towne had not proven that the standard contained an invalid delegation of legislative authority.  We agree, though for somewhat different reasons.

Both Towne and the Secretary cite a number of cases to support their positions.  Towne cites Gibson v. Berryhill, 411 U.S. 564, 578-79 (1973); Carter v. Carter Coal Co., 298 U.S. 238, 310-12 (1936); Eubank v. City of Richmond, 226 U.S. 137, 143-44 (1912).  There, the Supreme Court found unconstitutional delegations in statutes authorizing persons to develop regulations that their actual or potential competitors would be required to comply with.  Here, however, the crane manufacturer who developed the load chart was not an economic competitor of the crane user.  The cases cited by the Secretary can also be distinguished; for example, many do not involve delegations to private persons or businesses.[[2]]

Like Judge Burroughs, we find that other crane standards adopted by the Secretary, particularly 29 C.F.R. 1910.180(c)(1)(i)-(iv) and 1926.550(b)(2), cast more illumination on the delegation question.  Given these other standards, as explained more fully below, we conclude that the first sentence of section 1925.550(a)(1) can be validly applied in many cases.  We also conclude that Towne has failed to carry its burden of proving that section 1926.550(a)(1) is invalid as applied here.

On its face, section 1926.550(a)(1) appears to delegate authority to crane manufacturers.  The standard unambiguously states that employers "shall comply with the manufacturer's specifications and limitations applicable to the operation of. . .all cranes. . . ." The Secretary argues, however, that there is no true delegation in this case because OSHA regulations very closely prescribe the methods crane manufacturers must use in determining crane load limits.  This argument is generally sound.  Legally binding regulations can so closely circumscribe the discretion of a crane manufacturer in calculating load limits that it would be the government rather than the manufacturer that would be effectively prescribing the duty of a crane user.  This system of regulation need not be perfect.[[3]]  Furthermore, some reliance on manufacturers to calculate specifications for their products is unavoidable. Simply stated, the federal government must rely on private organizations to establish such specialized criteria as load charts because it would be neither practical nor efficient for the government to set or approve load-limit capacity tables for every model of crane in use.  This practical consideration deserves some weight.  See United States v. Dettra Flag Co., 86 F. Supp. 84, 87 (E.D. Pa. 1949).

We therefore note that the OSHA standards at 29 C.F.R. 1910.180(c)(1)(i)-(iv)[[4]] prescribe with specificity the procedures that crane manufacturers must follow in calculating load limits.[[5]]  In particular, section 1910.180(c)(1)(iii) requires the manufacturer to comply with SAE J765, Crane Load Stability Test Code (1967) [hereinafter cited as "SAE"], a "Recommended Practice" published by the Society of Automotive Engineers, Inc., reproduced as Appendix F of PCSA Standard No. 2, Mobile Hydraulic Crane Standards (1968) [hereinafter cited as "PCSA"], published by the Power Crane and Shovel Association.  That code is very detailed in describing how a crane load's limits are to be calculated.[[6]]  The manufacturer of a crane is therefore not left to his own devices in calculating load limits, but is answerable to the Occupational Safety and Health Administration through section 1910.180(c)(1)(i)-(iv) and SAE.  It therefore seems that crane manufacturers are so closely governed by OSHA standards that there is no delegation of authority.

Towne points out, however, that this crane was built in 1967, before the OSHA load limit standards became legally binding on the crane manufacturer.  Towne would apparently have us find that the load limit calculations reflected in the manufacturer's specifications booklet were made when the crane was built.  There is, however, no evidence to support that assumption; for one thing, the specifications booklet that Towne introduced into evidence is not dated.  If anything, the booklet suggests that the calculations were made after the crane was built.  The load limit chart compiled by the Grove Manufacturing Company evidently reflects the substance of sections 1910.180(c)(1)(i)-(iv).  For one thing, it prescribes that load limits may not exceed 85% of the tipping load.  This is precisely the percentage required by the OSHA standard at section 1910.180(c)(1)(i) and by the standard upon which it is based, section 5-1.1.1-a. of ANSI B30.5-1968, Safety Code for Crawler, Locomotive and Truck Cranes [hereinafter cited as "ANSI"], published by the American National Standards Institute.  See section 1910.189.  Yet, the predecessor of the 1968 ANSI standard, section 1311(a) of ASA B30.2-1943 (reaff'd 1952), published by the American Standards Association, prescribed only an 83% criterion.  For all this record shows, then, the crane manufacturer performed its calculations and supplied the chart to Towne after the crane was built and perhaps after the OSHA standard became binding on the manufacturer.  Given this gap in the record, and the fact that the burden of proving that the standard is invalid as applied is on Towne, George C. Christopher & Sons, Inc., 82 OSAHRC 9/A2, 10 BNA OSHC 1436, 1443, 1982 CCH OSHD 25,956, p. 32,531 (No. 76-647, 1982), we could not declare the standard invalid as applied.

Finally, even if the calculations were made when the OSHA requirements were not yet effective, we still would not be convinced that the standard is invalid as applied.   The validity of a delegation of legislative authority to a private party depends on its reasonableness when considered in light of the purpose of the statute or regulation and the facts of the case.  Male v. Ernest Renda Contracting Co., 64 N.J. 199, 314 A.2d 361 (1974), cert. denied, 419 U.S. 839 (1974).  On the whole, it would not offend reason or fairness to apply this load limit chart to Towne.  As we note above, the load limit chart for this crane reflects precisely those load-testing duties that the OSHA standard imposes.  Grove seems to have developed the chart according to the same criteria that are in the OSHA standard.  To require that a crane user in 1983 comply with a load limit chart based on those criteria is neither prejudicial, unreasonable, nor unfair.  To refuse to require it would be empty formalism.

We therefore conclude that Towne failed to meet its burden of proving that the standard is invalid as applied.

Existence of Violative Condition
As we have said, citation 1 alleges that the angle of the crane's boom was too shallow for the load.  Stated another way, the load was too great for the boom angle.  Judge Burroughs found this allegation proven.  We agree.[[7]]

Whether the crane was overloaded depends on the load exerted on the boom and the load capacity.  It is undisputed that the load exerted on the boom was at least 3,625 pounds.  This is the sum of 3,250 pounds--one-half of the weight of the steel mat, because one end of the mat remained on the floor; and 375 pounds--the full weight of the spreader bar, which comes between the lifting hook and the mat to permit a stable lift.[[8]]  The primary question therefore, what was the load capacity?

The crane manufacturer's specifications applicable to this lifting operation appear in a chart entitled "JIB CAPACITIES."  Both parties accept Judge Burroughs's finding that the jib of the boom was not offset; therefore, the capacity of the boom is found under the column "No Offset."  The chart provides:

MIN. BOOM         NO
ANGLE                  OFFSET
63 degrees               4000 pounds
50 degrees               2200 pounds

The boom here was at a 55 angle.  Neither the specifications nor the chart itself state how to interpret the chart if the actual angle of the boom is not listed.   Judge Burroughs interpolated between the 63 and 50 degree angles in the chart and calculated that the maximum permissible load for a boom at 55 degrees is 2,892 pounds.[[9]]

Straight-line interpolation is a mathematical technique for computing how much a change in one quantity will cause a change in a related quantity. It is often used intuitively and is sometimes known as the "proportional parts" method.  It assumes that the rate of change between two dependent variables is constant, that is, that a graph illustrating the relationship between the variables is a straight line.   Where, as here, the two variables follow a curved line rather than a straight line, straight-line interpolation can, nevertheless, yield a close approximation of the correct answer.[[10]]  Straight-line interpolation is also more practical to use by the ordinary crane operator at a construction site than curved-line interpolation, which requires one to plot points on graph paper and connect them with a french curve.   Using straight-line interpolation here reveals that the crane was overloaded by at least 878 pounds, that is by about 30 percent of its capacity.[[11]]

Towne objects, however, to the use of interpolation.  Towne argues that because the load chart does not tell an employer how to interpolate, the standard requiring use of the load limitations is unconstitutionally vague as applied.  This argument represents something of a shift in Towne's position.  Before the judge, it was the Secretary who had argued briefly against interpolation, maintaining that if the actual boom angle fell between two angles listed on the chart, the operator must stay within the load limit for the lower angle.  Towne argued to the contrary, observing that "industry practice. . .is to interpolate on the straight line basis," and that to require Towne to have instead used the next lowest angle would raise constitutional vagueness problems.  Judge Burroughs examined the arguments and stated that "[t]he view that the chart can be interpolated to determine the lifting capacity, as advocated by Towne, is affirmed."

We find no merit to Towne's current argument that it lacked fair notice of its obligation because the load chart does not tell an employer how to interpolate.   First, Towne's crane operator knew how to interpolate and actually used the technique.  Mark Shumaker, the crane operator, testified that he used the technique of straight-line interpolation to interpret the chart because he was told during a four-year apprenticeship training program offered by the International Union of Operating Engineers, Local 18, that it was a safe work practice.  Second, Judge Burroughs credited the testimony of Towne's expert witness Robert Bobel, a structural engineer, that straight-line interpolation is the practice followed by the construction industry in using load limit charts.  As the Secretary now observes, "[i]t is obvious. . .that everyone in the industry, and, in particular, this employer knew precisely what the [load chart] called for."  Towne's fair notice argument must therefore be rejected.   E.g., Owens-Corning Fiberglass Corp. v. Donovan, 659 F.2d 1285, 1288 (5th Cir. 1981) (proof of industry custom or employer's actual knowledge of requirements sufficient to reject vagueness argument).

We agree with Judge Burroughs that the load capacity of the crane was no more than 2892 pounds.  We find, moreover, that the load capacity of the crane was actually 490 pounds less than that, i.e., about 2400 pounds.  Charles Recard, a product safety and reliability engineer for Grove Manufacturing Co., testified that two steel plates weighing 170 pounds together had been added to each side of the boom at the nose, and that two steel plates weighing 320 pounds together had been added to the underside of the jib.  Recard stated that the crane manufacturer had not made the additions, and that the additional weight of the plates would reduce the load capacity.  Recard, an expert witness, testified that a conservative allowance would be to deduct the 490 pounds added by the steel plates from the load capacity.  Judge Burroughs held that the steel plates were not required to be added to the load because the steel plates were not "load handling devices" within the meaning of note 4 of the manufacturer's specifications booklet. However, an OSHA standard requires that the load capacity be reduced in this situation.  See section 1926.550(a)(16) (if modifications made to crane, capacity charts shall be changed accordingly).  Following the conservative approach employed by Mr. Recard, we find that the load capacity of this crane was about 2400 pounds, about 17 percent less than the normal load capacity at 55 degrees.

Towne argues that the crane could not have exceeded its load capacity because it did not tip over at the time of the accident.  Towne asserts that the manufacturer's specifications regard tipping as the capacity limitation, relying on note 1 of the crane's specifications booklet, which reads:

Rated lifting capacities are the maximum loads covered by the manufacturer's warranty with the machine standing on a firm, level and uniform supporting surface. Capacities do not exceed eighty-five 85% of tipping.  We agree with Judge Burroughs that Towne's contention lacks merit.  The plain meaning of the second sentence at note 1 of the specifications booklet is that rated lifting capacities are not more than 85% of the load that it would take to tip a crane.  This signifies that the tipping point of the crane is not the limit on the rated load capacity; rather, the rated load capacity would be no more than 85% of the tipping load.  See also ANSI 5-1.1.1-a.(margin of stability for load ratings is no more than 85 percent of truck-crane tipping loads; PCSA 7.03(1) and 7.12.1.).  And as Judge Burroughs noted, the rated load capacity could be even less than that.  That the crane did not tip therefore does not mean that the load limit was not exceeded.

In order to prove a violation, the Secretary must establish that Towne knew or could have known of the violative condition of the crane with the exercise of reasonable diligence.   E.g., Sasser Electric & Manufacturing Co., 84 OSAHRC 37/C6, 11 BNA OSHC 2133, 2135, 1984-85 CCH OSHD 26,982, p. 34,684 (No. 82-178, 1984), aff'd, No. 84-1961 (4th Cir. 1985).  We have found that Towne's crane was overloaded.  There is no evidence that Towne actually knew of the overloaded condition.  The issue here is therefore whether Towne could have known of it with reasonable diligence.  Judge Burroughs found that Towne could have known of the crane's overloaded condition had "[p]roper steps . . . been taken to insure an accurate computation of the total weight . . . ." We agree that Towne should have known of the overloaded condition of the crane.

We find that Towne critically failed to exercise reasonable diligence in two ways.  First, though the crane operator was still an apprentice, Towne did not supervise his calculation of load capacity or inform him of important information about the crane's load capacity.  Second, though Towne certainly should have known the weight of the load because it fabricated both the mat to be
lifted and the spreader bar, Towne did not clearly and unambiguously relay to the crane operator the precise, critical information.

As we have noted, the weight of the steel plates that had been added to the boom reduced the crane's load capacity by about 17 percent.  Yet, the crane operator testified that he did not know that any metal had been added to the jib or the nose of the boom. That Towne did not communicate the consequent reduction of load capacity to the crane operator shows a lack of reasonable diligence.  It ensured that the operator's load calculations would always be in error by about 17 percent.

We also find that Towne had no reliable means for unambiguously relaying critical information about the load to the operator.  On this point, the role of two Towne supervisors is important:  Mead Shumaker, Towne's vice-president, general superintendent, and safety officer; and Fred Dycus, the ironworker foreman.  Both men were at the jobsite when the overload occurred; the vice-president was in the company trailer, while the ironworker foreman was in the hole guiding the mat while it was being lifted. The vice-president testified that the replacing, repairing, and setting of the reinforced steel mats was the "direct responsibility" of ironworker foreman Fred Dycus.  However, Dycus denied at the hearing that he was the crane operator's foreman, stating that the placing of the mat "was up to" the crane operator.  Judge Burroughs recognized in his decision that it was the crane operator, not Dycus, who had been given the "last word" on the safe lifting of a load.   Nevertheless, the judge concluded that "[p]roper steps have been taken to insure an accurate computation of the total weight being lifted by the crane."

We agree with Judge Burroughs.  That Towne's highest supervisors on the site lacked a clear idea of who was to oversee the work of an apprentice crane operator is telling enough.  Moreover, though the vice-president and Dycus had particular knowledge of the weights of some components of the load, they did not reliably communicate that information to the crane operator.  We discuss here two instances of that.

The crane operator testified that he never knew that the spreader bar weighed.  According to the vice-president, the ironworker foreman had designed the spreader bar and had overseen its fabrication at the Timken site by Towne employees.  The vice-president had arranged to have the weight of the spreader bar calculated for Dycus by the structural manager.  The vice- president testified that the structural manager had told him that the spreader bar weighed about 375 pounds, and it was part of foreman Dycus' job to tell the crane operator what the spreader bar weighed.  Yet, because he was not told of the bar's true weight, the crane operator was left to make his "own visual estimate."  That the crane operator turned out to have overestimated the bar's weight the bar's weight as 500 pounds is fortunate but irrelevant.  The fact remains that the failure by Towne's supervisors to inform the crane operator of the spreader bar's true weight demonstrated such casualness as to amount to a lack of reasonable diligence.

Finally, Towne does not seem to have accurately assessed or communicated information about the weight of the mat, despite the fact that the mat was fabricated by Towne itself.  Ironworker foreman Dycus testified that he calculated the weight of the steel mat as 6,300 pounds, and he told the crane operator that.  Dycus testified also that he had overestimated the weight by what he thought was about 300 to 500 pounds because he had rounded off some figures.  In other words, Dycus had calculated the mat's weight to be 5,800 to 6,000 pounds but had added 300 to 500 to adjust for some rounded numbers.  It was, however, stipulated at the hearing that the mat actually weighed about 6,500 pounds (6,497.3 pounds, to be exact).  Therefore, Dycus had in fact underestimated the weight of the mat by at least 200 pounds.  More importantly, the crane operator testified that Dycus told him that the weight was around 6,000 pounds, which is 300 pounds less than what Dycus stated at he told the crane operator, and almost 500 pounds less than the mat's true weight.  Based on the record as a whole, we conclude that Towne failed to convey vital information to the crane operator.  We therefore find that Towne through its supervisors vice-president Shumaker and ironworker foreman Dycus could have known of the overloaded condition of the crane had it been reasonably diligent.  We thus affirm citation 1.

We also characterize the violation as serious under section 17(k) of the Act, 29 U.S.C. 666(k), because, as demonstrated by a fatality that occurred when the boom collapsed, there was a substantial probability that death or serious physical harm could result from the excessive load on the boom.  In light of the criteria in section 17(j) of the Act, 29 U.S.C. 666(j), particularly the gravity of the violation, we affirm the judge's assessment of a $240 penalty.

Citation 2:  29 C.F.R. 1926.550(a)(2), Failure
to Conspicuously Post Load Capacity Chart

In citation 2, the Secretary alleged that Towne violated 29 C.F.R. 1926.550(a)(2), which reads as follows:

1926.550 Cranes and derricks.

(a) General requirements.
* * *
(2) Rated load capacities, and recommended operating speeds, special hazard warnings, or instruction, shall be conspicuously posted on all equipment.  Instructions or warnings shall be visible to the operator while he is at his control station.
Judge Burroughs affirmed the citation.

It was undisputed that at the time of the accident the load capacity chart was not "conspicuously posted" on the crane.  Instead, it was in the crane operator's toolbox.  The crane operator had removed it from the door to the cab of the crane the day before in order to read the chart during lunch and, rather than replacing it, he put it in his toolbox.  The Secretary does not claim that Towne had actual knowledge that the capacity chart was no longer posted.  Therefore, the only issue on review is whether Towne could have known of that violative conduct with the exercise of reasonable diligence.  Towne argues that the crane operator's removal of the chart could not have been known with the exercise of reasonable diligence.  We agree.

Towne had a plan of periodic inspections of the crane.  About 3 weeks before the accident, Richard Mazeroski, an "oiler" employed by Towne, inspected the crane and found that the load chart was posted on the inside of the door to the crane's cab.  The crane operator stated that the chart was there when he took it to read the day before the accident.  It was not established that any supervisory employee of Towne would have had the opportunity to observe that the load chart was not posted inside the cab. Because Towne could not reasonably have known of the absence of the load chart, we vacate citation 2.

Accordingly, we affirm citation 1 and assess a penalty of $240, and vacate citation 2.


Ray H. Darling, Jr.
Executive Secretary

DATED:  DEC 4 1986

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[[1]] This standard was originally adopted under the Contract Work Hours and Safety Standards Act, 40 U.S.C. 327 et seq. (commonly known as the "Construction Safety Act").  36 Fed. Reg. 7340, 7383 (1971), adopting 29 C.F.R. 1518.550(a)(1), redesignated as 1926.550(a)(1), 36 Fed. Reg. 25232 (1971).  It was later adopted without further rulemaking under section 6(a) of the Occupational Safety and Health Act, 29 U.S.C. 655(a). 36 Fed. Reg. 10466 (1971), promulgating 29 C.F.R. 1910.12 (adopting by reference all Construction Safety Act standards).

[[2]] See Noblecraft Industries, Inc. v. Secretary of Labor, 614 F.2d 199, 203 (9th Cir. 1980) (delegation by Congress to the Secretary, not to private concern); Sorrell v. SEC, 679 F.2d 1323, 1325-26 & n.2 (9th Cir. 1982) (statute permitting private body to adopt rules and discipline its members subject to review and approval or disapproval by the Securities and Exchange Commission; no delegation to private party because ultimate authority in SEC); First Jersey Securities, Inc. v. Bergen, 605 F.2d 690, 697 (3d Cir. 1979), cert. denied, 444 U.S. 1074 (1980) (same); Todd & Co., Inc. v. SEC, 557 F.2d 1008, 1012-13 (3d Cir. 1977) (same); Pennsylvania Railroad Co. v. Sharfsin, 369 F.2d 276, 278-79 n.2, 283 (3d Cir. 1966), cert. denied, 386 U.S. 982 (1967) (railroad could discontinue route upon proper filing and waiting); and New Motor Vehicle Board of California v. Orrin W. Fox Co., 439 U.S. 96, 107-09 (1978) (statute conferred on automobile franchisees merely procedural right to delay action pending hearing).

[[3]] As Judge Burroughs observed:

[I]t is true that there is no absolute guarantee that any particular manufacturer will develop load limitations in strict compliance with the criteria specified . . . . [But] [t]here is no guarantee that any employer will follow any safety regulation promulgated by the Secretary.  This fact does not render the regulations invalid.

Cf. Northwest Airlines, Inc., 80 OSAHRC 87/B5, 8 BNA OSHC 1982, 1992, 1980 CCH OSHD 24,751, p. 30,490 (No. 13649, 1980) (that FAA private regulation system is not ideal is not reason to reject that procedure entirely; "no system that the FAA might follow would guarantee that airlines would always follow safe procedures.").

[[4]] Those standards provide (footnote on chart deleted):

(c) Load ratings--(1) Load ratings--where stability governs lifting performance.   (i) The margin of stability for determination of load ratings, with booms of stipulated lengths at stipulated working radii for the various types of crane mountings, is established by taking a percentage of the loads which will produce a condition of tipping or balance with the boom in the least stable direction, relative to the mounting.   The load ratings shall not exceed the following percentages for cranes, with the indicated types of mounting under conditions stipulated in subdivisions (ii) and (iii) of this subparagraph.

Type of crane mounting (percent of
Locomotive, without outriggers:
Booms 60 feet or less ...................... 85
Booms over 60 feet .......................... 85
Locomotive, using outriggers fully extended ................ 80
Crawler, without outriggers ......................................... 75
Crawler, using outriggers fully extended ..................... 85
Truck and wheel mounted without outriggers or
using outriggers fully extended ............. 85

(ii) The following stipulations shall govern the application of the values in paragraph (c)(1)(i) of this section for locomotive cranes:
(a) Tipping with or without the use of outriggers occurs when half of the wheels farthest from the load leave the rail.
(b) The crane shall be standing on track which is level within 1 percent grade.
(c) Radius of the load is the horizontal distance from a projection of the axis of rotation to the rail support surface, before loading, to the center of vertical hoist line or tackle with load applied.
(d) Tipping loads from which ratings are determined shall be applied under static conditions only, i.e., without dynamic effect of hoisting, lowering, or swinging.
(e) The weight of all auxiliary handling devices such as hoist blocks, hooks, and slings shall be considered a part of the load rating.
(iii) Stipulations governing the application of the values in paragraph (c)(1)(i) of this section for crawler, truck, and wheel- mounted cranes shall be in accordance with Crane Load-Stability Test Code, Society of Automotive Engineers (SAE) J765.
(iv) The effectiveness of these proceeding stability factors will be influenced by such additional factors as freely suspended loads, track, wind, or ground conditions, condition and inflation of rubber tires, boom lengths, proper operating speeds for existing conditions, and, in general, careful and competent operation.  All of these shall be taken into account by the user.

[[5]] The Judge relied on 29 C.F.R. 1926.550(b)(2) which requires that "[a]ll . . . truck . . . cranes in use shall meet the applicable requirements for design, . . .testing, . . . and operation as prescribed in the ANSI B30.5-1968, Safety Code for Crawler, Locomotive and Truck Cranes."  However, section 1926.550(b)(2) applies only to employers in the construction industry, and not to crane manufacturers generally. See 29 C.F.R. 1910.12(a) (defining "construction work").   Section 1910.180 is therefore the pertinent section in determining what legal requirements constrain crane manufacturers when they calculate load limits.

[[6]] The PCSA standard is incorporated by reference as an OSHA standard at 29 C.F.R. 1926.550(a)(17).

[[7]] Towne argues that evidence as to the structural weakness of the boom should be considered.  The issue before us is not what caused an accident, but whether a violation of an OSHA standard occurred.  See, e.g., Concrete Construction Corp., 76 OSAHRC 47/A2, 4 BNA OSHC 1133, 1135, 1975-76 CCH OSHD 20,610, p. 24,664 (No. 2490, 1976); see also The Boeing Co., 77 OSAHRC 188/D13, 5 BNA OSHC 2014, 2016, 1977-78 CCH OSHD 22,266, p. 26,809 (No. 12879, 1977).  Inasmuch as evidence on the structural integrity of the boom is irrelevant to the issues before us in this case, we do not consider it.

[[8]] The parties dispute whether the 145-pound headache ball that was attached directly over the hook should have been included in the load.  Note 4 of the manufacturer's specifications booklet states that "[t]he weights of all load handling devices are considered part of the load lifted and suitable allowances for them should be made."  We find it unnecessary to resolve this dispute because we find that the crane was overloaded even if the headache ball were excluded.

[[9]] The load chart states that the crane has a 2200 pound capacity at 50 degrees and a 4000 capacity at 63 degrees.  Inasmuch as a 13 degree difference in boom angle corresponds to a 1800 pound difference in load capacity, one can say that for loads between 2200 and 4000 pounds, there is a 138.46 pound increase in capacity per degree (1800/13).  Therefore, the capacity at 55 degrees is 692 pounds (5 x 138.46) greater than the capacity at 50 degrees, that is, 692 + 2200 = 2892 pounds.

[[10]] That the two variables here follow a curved line is apparent from the load limit chart, for the ratio of the change in capacity to the change in corresponding boom angle varies between the entries in the chart.  Also, when the entries in the chart are plotted as points on graph paper, the points form a curved line.   Curved-line interpolation from such a graph shows that the capacity at 55 degrees is about 2600 pounds.  Our finding that the crane was overloaded does not depend on this figure because the Secretary has not sought to predicate a violation on figures derived from curved-line interpolation; we will instead continue to employ the figure derived from straight-line interpolation, which is more favorable to Towne.

[[11]] Actually the crane was more overloaded than that.  Some of the reasons for this are discussed below.