Daily Rules, Proposed Rules, and Notices of the Federal Government
This preamble to the final rule for VTLs in the Longshoring and Marine Terminals Standards discusses the events leading to the adoption of the standard, the necessity for the standard, and the rationale behind the specific provisions set forth in the final rule. The preamble also includes the Final Economic and Regulatory Flexibility Analysis, a summary of the paperwork issues under the Paperwork Reduction Act of 1995, and sections on other requirements necessary for an OSHA standard. The discussion follows this outline:
The following acronyms and abbreviations have been used in this document:
Since the 1970s, intermodalism (the containerization of cargo) has become the dominant mode of cargo transport in the maritime industry, replacing centuries-old, break-bulk cargo handling. In the marine cargo handling industry, intermodalism typically involves three key components: standardized containers with uniform corner castings; interbox connectors (such as SATLs) to secure the containers (to each other at the four corners, to the deck of the ship, to a railroad car, or to a truck chassis); and a type of crane called a container gantry crane that has specialized features for the rapid loading and unloading of containers. Because intermodalism is highly dependent on standardized containers and connecting gear, several international organizations have developed standards for equipment and practices to facilitate intermodal freight operations. This helps ensure that containers and interbox connectors are sized and operate properly so that containers and connectors from different manufacturers will fit together.
The International Organization for Standardization (ISO) is a worldwide federation of national standards bodies whose mission is to promote the development of international standards to reduce technical barriers to trade. There are several ISO standards addressing the design and operational handling of intermodal containers and interbox connectors. In particular, ISO 3874,
The VTL issue has been evolving for many years. The following table shows the progression of events:
The issue of vertical tandem lifting was first raised to OSHA by Matson Terminals, Inc. In 1986, through a series of meetings and correspondence with OSHA (Exs.
The [Compliance Safety and Health Officer] must be mindful of the manufacturer's specifications and endorsements, the Matson engineering technical specifications, the ABS Test Report, as well as, maintained conditions of the corner posts, the twist locks, the cones, the containers and the hoisting and/or lifting devices. [Ex. 40-8]
In 1993, OSHA received a letter from Sea-Land Service, Inc., requesting that OSHA interpret its existing longshoring standards to allow the lifting of two empty 12.2-meter (40-foot) ISO freight containers that were vertically coupled using SATLs (Ex. 1). OSHA's standards had not changed since OSHA's letter to Matson. In its response, OSHA allowed Sea-Land to handle two empty containers vertically connected, if eight requirements were met (Ex. 2, hereinafter called “the Gurnham letter”). The requirements were developed by OSHA's Directorate of Compliance Programs (now called the Directorate of Enforcement), taking into account applicable OSHA standards and related industry practices associated with container cargo handling operations. These eight requirements were: inspecting containers for visible defects; verifying that both containers are empty; assuring that containers are properly marked; assuring that all the SATLs operate (lock-unlock) in the same manner and have positive, verifiable locking systems; assuring that the load does not exceed the capacity of the crane; assuring that the containers are lifted vertically; having available for inspection manufacturers' documents that verify the capacities of the SATLs and corner castings; and directing employees to stay clear of the lifting area.
In 1994, OSHA addressed VTLs briefly in the preamble to the proposed revisions to the Marine Terminals and Longshoring Standards (29 CFR Parts 1917 and 1918, respectively; 59 FR 28594, June 2, 1994), stating: “In those situations where one container is used to lift another container, using twistlocks, then the upper container and twist locks become, in effect, a lifting appliance and must be certified as such” (59 FR 28602, June 2, 1994). OSHA received comments on this issue only from the International Longshore and Warehouse Union (Exs. 4, 5, 6). Although these comments favored the proposed interpretation and requested that the Agency include it as a requirement in the regulatory text, they included no specific information regarding the hazards of VTLs of two containers using SATLs. Sea-Land submitted a detailed six-page comment (Ex. 7) addressing a number of the proposed changes to the Marine Terminals and Longshoring Standards, but did not address VTLs. OSHA received a late, posthearing submission from the International Longshoremen's Association, however, that alerted the Agency to what might be a serious problem with this type of lift, citing several incidents at U.S. ports where failures had occurred (Ex. 8-A). While OSHA did not rely on this letter in issuing the final rule because it was not a timely submission to the record, the letter made OSHA aware of safety concerns that might need to be addressed through supplemental rulemaking. Because of a lack of information on the safety considerations, cost impacts, and productivity effects of VTLs, as well as on the capability of containers and SATLs to withstand such loading, OSHA reserved judgment on the appropriate regulatory approach to this practice, pending further study (62 FR 40142, 40152, July 25, 1997).
Until the publication of the final Longshoring and Marine Terminals Standards in 1997, OSHA viewed the lifting of one container by another container using SATLs as similar to a container spreader picking up a single container using the spreader's twistlocks. Although the terms “semi-automatic twistlocks” and “spreader-bar twistlocks” appear similar, they refer to two very distinct items. SATLs were designed to connect and secure intermodal containers that are stowed on the deck of a vessel. They are generally made of a cast metal with a surface that has not been finely honed. By contrast, a spreader-bar twistlock is an integral part of a gantry crane's container spreader. It has a similar appearance to a SATL, but is made of forged metal with a machined surface. These twistlocks are typically locked and unlocked with hydraulic power and are used as part of the gantry crane to lift and move containers.
In lifting the bottom container in a VTL, the upper container serves the same role as a container spreader on a gantry crane, and the SATLs perform the same function of holding the bottom container, as do the twistlocks on the container spreader bars.
A gantry crane's container spreader bars are considered a “lifting appliance,” according to the International Labor Organization (ILO) Convention 152 Dock Work, portions of which OSHA incorporated or adopted in the Longshoring Standards in 29 CFR Part 1918. The ILO is a specialized, independent agency of the United Nations with a unique tripartite structure of business, labor, and government representatives. Its mandate is to improve working conditions (including safety), create employment, and promote workplace human rights,
On October 9, 1997, OSHA reopened the VTL record with a
Shortly after the January public meeting, OSHA decided on a multifaceted approach to resolve the questions raised during the public meeting:
a. Contract with the National Institute of Standards and Technology (NIST) to conduct engineering studies about the strength and durability of container corner castings and SATLs;
b. Meet with the International Cargo Handling and Coordination Association
c. Meet with the ILO to clarify the ambiguity in existing interpretations of ILO Convention 152;
d. Monitor the ISO deliberations regarding VTLs; and
e. Form a workgroup within the Maritime Advisory Committee for Occupational Safety and Health (MACOSH) to address issues relating to VTLs and report back to MACOSH.
MACOSH was chartered by the Secretary of Labor to advise OSHA on matters relating to occupational safety and health standards in the maritime industries. MACOSH members include representatives of employers, employees, State safety and health agencies, a designee of the Secretary of Health and Human Services, and other groups affected by maritime standards. During a MACOSH meeting held in Hampton, Virginia, on September 22 and 23, 1998, a VTL workgroup was formed consisting of the MACOSH longshore employer and employee representatives, with participation by many other interested stakeholders. Over the next several years, the VTL workgroup discussed VTL issues at informal working group meetings and during MACOSH meetings.
On September 28, 1998, members of MACOSH's VTL workgroup met with ICHCA in Malmö, Sweden, to discuss the VTL issue. This was followed by a meeting with ILO in Geneva, Switzerland. The discussion with the ILO focused on the issue of determining whether the components of a VTL (the upper intermodal container and the SATLs) are either a “lifting appliance” or “loose gear” within the meaning of the relevant international standards. On October 21, 1998, an ILO official indicated to OSHA that the ILO considers SATLs used for lifting to be loose gear, and that it considers the upper container to be merely part of the load, rather than loose gear or a lifting appliance (Exs. 31, 32). The significance of this decision is that as loose gear, under ILO Convention 152, SATLs must be tested and inspected before initial use and reinspected on an annual basis, and the containers have no additional inspection requirements. Lifting appliances, on the other hand, must be retested at least once every 5 years. Retesting of a lifting appliance in a VTL would require that a specific container and four specific SATLs used for VTLs be proof-load tested before initial use and every 5 years thereafter. As mentioned previously, this would be almost impossible to do.
During a MACOSH meeting held at the U.S. Merchant Marine Academy, Kings Point, New York, in July 1999, Dr. H.S. Lew of NIST presented a report on the strength of SATLs, latchlocks (a device similar in usage to a SATL, but of a different design), and container corner castings (Ex. 40-10). Dr. Lew's study indicated that the SATLs he tested were very substantial with load capacities ranging from 562 to 802 kN and that the container corner castings were more likely to deform and fail before the SATLs. However, he expressed reservations about the use of latchlocks as interbox connectors. This particular type of interbox connector has a smaller bearing surface in contact with the corner casting. In Dr. Lew's opinion, this makes it more likely that, if the spring-loaded latch does not extend fully inside the container corner casting, it could slip through the hole in the corner casting when under load, such as when lifting another container. Even when the lock of a latchlock was fully extended, the NIST study determined that its surface area was insufficient to safely perform VTLs. In regard to the strength of SATLs, the conclusions of the NIST study were similar to a Swedish study (Ex. 11-6 H) that was conducted in 1997 by the Swedish National Testing and Research Institute. (For an extended discussion of these studies see the discussion of the issue titled “Strength of the container-connector system” under section O, Summary and Explanation of the Final Rule, later in this preamble.)
On September 8, 2000, the U.S. delegation to ISO Technical Committee Number 104 Freight Containers (ISO/TC 104) held a meeting in Washington, DC, primarily to discuss the U.S. position on VTLs for the ISO biennial meeting to be held in October. After this meeting, OSHA sent a letter to the Chairman of ISO/TC 104 addressing concerns such as safety factors, the use of latchlocks, and the lack of operational procedures (Ex. 40-11).
At their biennial meeting in Cape Town, South Africa, in October 2000, the ISO/TC 104 agreed that SATLs, which previously were only used for securing containers, could be used to lift containers. However, ISO/TC 104 did not address the question of how to use SATLs safely for such lifting, because ISO does not issue standards for operational procedures. In response to safety concerns in this area, ISO/TC 104 passed a resolution requesting that ICHCA, a member of ISO/TC 104, develop operational guidelines for VTLs. ICHCA agreed to work on such guidelines.
In May 2002, ISO formally adopted language allowing SATLs that meet certain conditions to be used for lifting:
The vertical coupling of containers that are not specifically designed as in 6.2.4 [ISO 3874] for lifting purposes, using twistlocks or other loose gear, is acceptable if forces of not greater than 75 kN [Footnote 1]) act vertically through each corner fitting, and the twistlocks or other loose gear used are certified [Footnote 2]) for lifting. The twistlocks or other loose gear shall be periodically examined. [Ex. 40-9]
Footnote 1 stated:
The value of 75 kN prescribes the minimum structural capability of the lock/corner fitting combination. The 75 kN value includes an arbitrary constant wind load of 26 kN (corresponding wind speed of 100 km/h), regardless of the size of the containers. As an example, the balance of the 75 kN value equates to two 1 AAA containers with a combined tare of 22 kN and a maximum payload of 27 kN. A practical upper limit of three vertically-coupled containers is also envisaged.
Footnote 2 stated:
The certification process envisaged is to use a safety factor of at least four based on the ultimate strength of the material.
Essentially, this meant that, based on the strength of the SATLs and the containers, the ISO standard would allow VTLs to consist of up to three containers with a total load weight of 20 tons.
In January 2001, as agreed to at the Cape Town meeting, an ICHCA VTL workgroup met in London to begin drafting operational guidelines for VTLs. The ICHCA workgroup finalized their VTL guidelines (Ex. 41) in September 2002 and received final approval by ICHCA's Board of Directors in January 2003. OSHA gave careful consideration to the ICHCA guidelines in the drafting of the proposed and final standards for VTLs.
The purpose of the OSH Act is to “assure so far as possible every working man and woman in the nation safe and healthful working conditions and to preserve our human resources” (29 U.S.C. 651(b)). To achieve this goal, Congress authorized the Secretary of Labor to issue and to enforce occupational safety and health standards. (See 29 U.S.C. 655(a) (authorizing summary adoption of existing consensus and federal standards within two years of the OSH Act's enactment); 655(b) (authorizing promulgation of standards pursuant to notice and comment); and 654(d)(2) (requiring employers to comply with OSHA standards)). A safety or health standard is a standard “which requires conditions, or the adoption or use of one or more practices, means, methods, operations, or processes, reasonably necessary or appropriate to provide safe or healthful employment or places of employment” (29 U.S.C. 652(8)).
A standard is reasonably necessary or appropriate within the meaning of section 3(8) of the OSH Act if it substantially reduces or eliminates significant risk; is economically feasible; is technologically feasible; is cost effective; is consistent with prior Agency action or is a justified departure; is supported by substantial evidence; and is better able to effectuate the Act's purposes than any national consensus standard it supersedes (29 U.S.C. 652). (See 58 FR 16612, 16616 (3/30/1993)).
A standard is technologically feasible if the protective measures it requires already exist, can be brought into existence with available technology, or can be created with technology that can reasonably be expected to be developed. American Textile Mfrs.
A standard is economically feasible if industry can absorb or pass on the cost of compliance without threatening its long term profitability or competitive structure. See
Section 6(b)(7) of the OSH Act authorizes OSHA to include among a standard's requirements labeling, monitoring, medical testing and other information gathering and transmittal provisions (29 U.S.C. 655(b)(7)).
All safety standards must be highly protective. (See, 58 FR 16614-16615;
OSHA has developed this final rule in light of international trade considerations. In the Trade Agreements Act of 1979 (“TAA,” codified at 19 U.S.C. 2501
If the demonstrable purpose of the standards-related activity is to achieve a legitimate domestic objective including, but not limited to, the protection of legitimate health or safety, essential security, environmental, or consumer interests and if such activity does not operate to exclude imported products which fully meet the objectives of such activity.
Mindful of these international aspects, OSHA has sought to formulate a protective but flexible approach to VTLs in the final rule. As discussed in further detail below, OSHA's requirements for VTLs are consistent with the relevant provisions of ILO Convention 152 and with many of the provisions of the ISO standard and ICHCA guidelines.
Several commentators suggested that deviations from the ICHCA guidelines and ISO standards for VTLs would create unnecessary barriers of trade in violation of the above provisions (Exs. 47-5; 54-2). OSHA does not agree. First, these commenters' positions seem to be premised on the assumption that there is an international consensus about whether to perform VTLs and how they are to be performed. OSHA finds that the record does not support that assumption. While two international bodies have addressed VTLs (ICHCA and the ISO), the ILO refused to adopt provisions allowing VTLs in its Code of Practice (Exs. 47-4, 50-7, 64). Further the record suggests that VTLs are not performed at many ports worldwide. Submissions indicate, without contradiction, that VTLs are not performed in Canada, Tokyo, Rotterdam, Antwerp, and Russia (Tr. 2-285, 2-295; Ex. 62). Maersk stated that it performs VTLs in only 8-10 of its 80 ports of call (Tr. 2-127 to 128). ICHCA's guidelines specifically note that national legislation may prohibit or limit VTLs (Exs. 41, 18.104.22.168 22.214.171.124).
Regardless, OSHA does not believe that limiting VTLs to two empty containers creates a “barrier to trade” under the TAA. These requirements are applied to vessels regardless of origin and apply to ships arriving from U.S. ports as well as foreign ports. OSHA's regulation does not discriminate, either on its face or in effect, by country of origin or class of shipper. As indicated in the Final Economic Analysis below, the claim that the final rule “constitutes a barrier of trade seems to be without merit in any economic sense.”
Moreover, even if the regulation did constitute a barrier to trade, it still would not be “unnecessary” in the sense of the TAA. As discussed at length in the Summary and Explanation, OSHA has given extensive
OSHA has also given consideration to the relevant international standards in the area, as required by the TAA (see 19 U.S.C. 2532(2)). Articles 21 through 27 of ILO Convention 152 contain international standards for vessel cargo handling gear, which are intended to protect dockworkers. The United States is not a signatory to either this convention or its predecessor, ILO Convention 32. However, it has nonetheless conformed to them through regulations promulgated by the U.S. Coast Guard, regarding inspected U.S. flag vessels, and by OSHA, regarding other vessels (62 FR 40152). In particular, in its latest revisions to its Longshoring Standard, OSHA updated its vessel cargo handling gear certification requirements to conform to Convention 152's requirements (62 FR 40151-54; 29 CFR 1918.11).
VTLs were not used at the time that Convention 152 was drafted, (Tr. 1-207), and as noted above, there was substantial uncertainty about how it applied to this procedure at the time OSHA revised its Longshoring Standard in 1997 (see 62 FR 40152-53). This engendered substantial study of VTLs, both by OSHA and the international community, as detailed elsewhere in this preamble. The result of this study is that, although the ILO has since clarified that twistlocks used in VTLs are loose gear under Convention 152, VTLs represent a unique cargo operation. The rules and guidance developed by ICHCA and ISO TC 104 reflect an adaptation of Convention 152's loose gear rules for VTLs, given the particular safety issues they pose, rather than a direct application of its requirements. Thus, for example, where the convention at Article 23 requires that loose gear to be “thoroughly examined and certified” every twelve months, ISO 3874 Amend. 2 requires only that twistlocks used in lifting be “periodically examined” (Ex. 40-9), and ICHCA would allow for a continuous inspection program of such twistlocks (Exs. 41, 126.96.36.199.3 188.8.131.52.4).
The final rule takes the same approach towards the convention in formulating rules for VTLs. In most respects—such as keeping twistlocks in good repair and working order, testing and certification before initial use, marking, and inspection before each use—the final rule's requirements are consistent with the convention's. The only significant departure is in the area of the annual thorough examination required by Article 23. Rather than require an annual thorough examination, OSHA has determined that all the necessary elements of a thorough examination of a twistlock may be performed before each lift (see Summary and Explanation below). It has thus required that these examinations to be performed before each lift and this has rendered an annual thorough examination and certification unnecessary. If anything, OSHA's approach may be more protective than that required by the convention.
Convention 152 itself allows variances if the change in question is not less protective (Art. 2.2; Ex. 41, 5.2.6), and as noted above, several international bodies have made their own departures from the annual thorough examination and certification requirement in this context. ICHCA has noted that under the convention: “It is understood that some countries may impose a higher standard,” (Ex. 41, 5.2.6), and some countries have already done exactly that (62 FR 40154). OSHA believes that the final rule is within the letter and spirit of ILO Convention 152, and it is therefore continuing its practice of maintaining consistency with the convention.
OSHA also considered ISO 3874 and the ICHCA VTL guidelines in the formulation of this final rule. While consistent in some ways with these documents, the final rule differs from them in at least two significant aspects: It allows VTLs only of empty containers, and it allows VTLs of only two containers—three container VTLs are prohibited. Nonetheless, this result is consistent with the TAA. As comprehensively explained in the Summary and Explanation, the record shows that ICHCA and ISO TC 104 used assumptions (e.g., the number of twistlocks engaged in a VTL and the acceleration forces experienced at the beginning of the lift) that did not adequately represent the forces experienced by corner castings and twistlocks in use. OSHA has used more appropriate assumptions in formulating its final rule. Therefore, OSHA has determined that for the purposes of the TAA, ISO 3874 Amend. 2 and the ICHCA guidelines (to the extent they may be considered an “international standard” for purposes of the TAA) are not “appropriate” standards upon which to base this final rule because they do not adequately protect “human health or safety, animal or plant life or health or the environment” (19 U.S.C. 2432(2)(B)).
An issue in any OSHA rulemaking is significant risk. In its Notice of Proposed Rulemaking (NPRM), the Agency preliminarily concluded that the procedures required in the proposal would substantially reduce the risk to employees of performing VTLs (68 FR 54298, 54302, September 16, 2003). Mr. Ronald Signorino, who testified at the July 29-30, 2004, hearing on the proposed rule on VTLs as a member of a panel representing the United States Maritime Alliance (USMX), remarked that, before OSHA promulgates a standard, it must find that a significant risk is present and can be eliminated or lessened by a change in practice (Ex. 54-2). He argued that the Agency had not made that threshold finding, as follows:
There is no evidence in the record which establishes that VTL[s] are unsafe and that operational limitations over and above those appearing within international standards and guidelines are warranted. [Ex. 54-2]
As Mr. Signorino noted, the Supreme Court has held that before OSHA can promulgate any permanent health or safety standard, it must make a threshold finding that significant risk is present and that such risk can be eliminated or lessened by a change in practices (
The Act allows OSHA considerable latitude to devise means to reduce or eliminate significant workplace hazards. Clearly, OSHA need not make individual quantitative or qualitative risk findings for every regulatory requirement in a standard. Once OSHA has determined that a significant risk of
While OSHA often uses fatality, injury, and illness reports and statistics to support its findings of significant risk, the finding of significant risk does not strictly require a history of injury. As Mr. Signorino noted, there is no evidence in the record of this rulemaking showing a worker injury due to VTL, despite the thousands of lifts that have occurred in the U.S. since 1986. However, evidence in the record does support a finding of significant risk for unregulated VTL operations. First, and foremost, as described in detail later in this preamble,
Second, the industry has acknowledged that VTLs are riskier than single lifts. As discussed in the background section of the ICHCA guidelines, ISO Technical Committee 104 recognized that there were potential hazards associated with VTL operations, and the committee asked ICHCA to develop a comprehensive document to deal with all aspects of VTL operations (Ex. 41). This acknowledgment was reinforced by the comments of Jimmy Burgin on behalf of the National Maritime Safety Association (NMSA) and the Pacific Maritime Association (PMA), who stated, “As an initial matter the TC [NMSA technical committee] recognized that VTL operations are different, and must be treated differently than, normal single container lifts” (Ex. 50-9). In addition, several individual companies testified that they follow the ICHCA guidelines to help assure the safety of VTL operations (see for example, Tr. 2-103), and some companies supplement the ICHCA guidelines with additional procedures to assure safe VTL handling (see for example, Tr. 2-128).
Third, the handling of individual containers has been determined in previous rulemakings to include risk (62 FR 40142-40144). The lifting of two or more containers cannot be less risky. VTLs introduce additional risk because more equipment can fail (twistlocks, corner castings, the container itself), the loads have a greater sail area that can be affected by wind, the loads have more sway, and VTLs are more difficult to transport on the ground. Also, compared to single lifts, the greater bulk of VTLs obscures more of the crane operator's view and thus potentially increases the likelihood of accidents. Finally, the safe transport of oversize loads and containers is recognized to require special procedures by other transportation interests, such as railroads and highway authorities (see, for example, 43 Texas Administrative Code, Chapter 28, Subchapters A-G).
Fourth, as discussed in detail in the next section of this preamble, OSHA's analysis of the strength of the components involved in VTLs demonstrates that lifting loaded containers in a VTL or lifting more than two containers in a VTL poses a significant risk of failure. It is widely a recognized engineering practice to impose sufficient factors of safety to ensure the safe lifting of cargo. An inadequate safety factor would result in significant risk. Without regulation, the Agency believes that employers would have an economic incentive to lift larger loads in VTLs, either by lifting loaded containers or by lifting more than two vertically coupled containers at the same time, thus reducing the safety factor to unacceptable values and causing a significant risk.
Thus, OSHA finds that VTLs pose a significant risk of injury to workers. The Agency notes that this finding of significant risk is proactive rather than reactive. It anticipates the possibility of injury and death that could result from VTLs conducted without special safety precautions and will regulate those problems before a worker is injured or killed.
OSHA also concludes that the final rule will substantially reduce that risk. Currently, employers are performing VTLs under the Gurnham letter (Ex. 2), which permits VTLs under conditions similar to those contained in the final rule. Several rulemaking participants, including Dennis Brueckner, representing the International Longshore and Warehouse Union (ILWU) Coast Safety Committee, testified that employers were not meeting the conditions set out in that letter when conducting VTLs (Tr. 2-369, 2-386, 2-407—2-408). By promulgating this final rule, the Agency anticipates that the percentage of employers complying with these conditions will increase.
Furthermore, the final rule includes additional provisions ensuring that interbox connectors are sufficiently strong so that they withstand, without failure, the forces that may be imposed during a VTL and provisions ensuring that inspections of interbox connectors, corner castings, and containers are conducted immediately before the lift. By ensuring that this equipment is adequately strong and in good condition immediately before a VTL, the final rule will substantially reduce the probability of failure and resulting accidents and injuries.
This section of the preamble discusses the important elements of the final standard and explains the purpose of the individual requirements. This section also discusses and resolves issues raised during the comment period, significant comments received as part of the rulemaking record, and any substantive changes that were made from the proposed rule. References in parentheses are to exhibits in the rulemaking record (Ex.) or to page numbers in the transcript of the public hearing held on July 29 and 30, 2004 (Tr.) or the Agency's public meeting on VTLs in January 1998 (1998-Tr.).
OSHA originally proposed (68 FR 54298) to permit VTLs, that is, the lifting of two partially loaded intermodal containers, one on top of the other, connected by semi-automatic twistlocks or other interbox connectors under certain stated conditions. The proposal would have allowed VTLs with a maximum total weight of 20 tons (combined weight of the containers and cargo). The proposal also imposed a safe working load requirement for interbox connectors used in VTLs, based on ICHCA recommendations, of 10,000 kg.
Several rulemaking participants strongly objected to OSHA's proposal to permit VTLs of two partially loaded containers (Exs. 8A, 10-1, 11-1B, 11-1C, 11-1G). These rulemaking participants submitted considerable evidence on the safety of VTLs. In light of these objections and this evidence, OSHA has reconsidered the basis on which the Agency preliminarily concluded that lifting two partially loaded containers in tandem is safe.
After considering all of the evidence in the record, OSHA has concluded that the safety of VTLs can only be ensured under ICHCA's safe working load requirements when a maximum of two empty containers are lifted. Evidence submitted to the record reveals that a sufficient margin of safety does not exist, in all situations, when a combined load of up to 20 tons is hoisted in a VTL. In particular, operational considerations and dynamic forces limit the maximum load that can be safely lifted, as discussed fully later in this section of the preamble.
In a VTL, the uppermost container, its bottom corner castings, the interbox connectors, and the upper corner castings of the next lower container must be capable of supporting whatever loads are imposed by containers below the top one. Similarly, if more than two containers are lifted at a time, the intermediate containers, corner castings, and interbox connectors must be capable of supporting all loads below them. Thus, the strength of the container itself and the interbox connector-corner casting assembly is a key issue in the determination of whether VTLs are safe and, if so, under what conditions.
Drawings of a semi-automatic twistlock and the connection between twistlocks and corner castings are shown in Figure 1 and Figure 2. It should be noted that the load-bearing surface area is limited to the overlap between the flat surface of the cone of the twistlock and the inside surface of the corner casting at the top or bottom of the opening. The load-bearing surface area is shown in Figure 3.
An explanation of basic strength of materials theory will clarify the underlying principles on which OSHA is basing its determination in this rulemaking.
Stress is a measure of force per unit area within an object. It is the object's internal distribution of force per unit area that reacts to external applied loads. In the following discussion, stress is measured in newtons per square meter (N/m
Strain is an expression of the deformation caused by the action of stress on an object. It is a measure of the change in size or shape of the object. In the following discussion, strain is unitless, though the amount of strain is sometimes given as a percent.
Stress may be applied to a material in a number of ways, including tension, compression, and shear. Compressive stress is stress applied so as to compress the material. Shear stress is stress applied parallel or tangential to the face of the material. Tensile stress, which is the primary concern in this rulemaking, is stress applied to pull a material apart. This is the predominant type of stress that a twistlock experiences during a VTL. The corner casting also experiences compressive and shear stress.
When material is stressed by the application of a tensile force, it will stretch and, when the stress is removed, return to its original size and shape as long as the stress is below the yield strength of the material. When the applied stress exceeds the yield strength of the material, it permanently deforms. When the stress exceeds the ultimate strength of the material, it catastrophically fails, or ruptures. A typical stress-strain curve is depicted in Figure 4.
To limit the forces on a component to a safe level, engineers usually set a maximum stress limit on the material at a value much less than its yield strength. This is done using maximum rated loads and safety factors. A maximum rated load is the highest load permitted to be carried by the component. A safety factor is the ultimate strength
ISO Technical Committee on Freight Containers, Technical Committee 104, develops international standards for the design and testing of freight containers and for container handling and securing (Ex. 41). Standards under the purview of ISO/TC 104 deal with structural issues that relate to the ability of a freight container to be handled and safely transported (Ex. 41). Table 1 lists the relevant ISO/TC 104 standards that relate to VTLs.
ISO 1161 sets detailed specifications for the dimensions, design, and strength of corner castings. The design requirements in this standard call for top corner castings to have design loads for lifting of 150 kN. Bottom corner castings are in most significant respects identical to top corner castings. Therefore, they can be expected to have the same strength.
ISO 1496-1 sets specifications for Series 1 freight containers. The requirements in this standard ensure that such containers are adequately strong for the lifting and in-use conditions they are likely to experience.
ISO 3874 sets requirements for the dimensions and strength of twistlocks. This standard requires twistlocks to have a minimum load-bearing surface of 800 mm
OSHA had relied on two studies, a Swedish National Testing and Research Institute's (SNTRI) study, “Container Lashing” (Ex. 11-6H), and a NIST study, “Strength Evaluation of Connectors for Intermodal Containers” (Ex. 40-10), to support its proposal. The Swedish study focused primarily on the ability of containers, interbox connectors, and lashing equipment to withstand the forces likely to be imposed while being transported aboard a vessel. However, both studies evaluated the strength of interbox connectors and corner castings.
The NIST study included site visits to port facilities and laboratory tests of interbox connectors. At the time of the NIST study, approximately 12 manufacturers produced most of the interbox connectors used by the shipping industry. NIST contacted U.S. representatives of eight manufacturers, and four provided interbox connectors for testing. For the failure load test of connector shafts loaded in tension, two new interbox connectors were used from each of the four manufacturers, and two used interbox connectors were used from two of the four manufacturers, for a total of 12 interbox connectors.
Test specimens included semi-automatic twistlocks and latchlocks. The engineering study included the testing of twistlocks in tension, twistlock and latchlock assemblies with corner castings in tension and compression, and shafts of twistlocks in tension to obtain the stress-strain relationship. In addition, NIST measured the bearing surface areas of the top and bottom cones of twistlocks and latchlocks on the inner surfaces of the corner castings.
The NIST study revealed that the ultimate tensile loads
[T]he capacity of the assembly is limited by failure of the corner fitting. Failure was brought about by large permanent deformations of the aperture of the corner fitting and/or shearing at the perimeter of the aperture * * * A relatively small bearing area of the cone on the corner fitting caused a concentration of force near the edge of the aperture, and as a result, the edge of the cone sheared through the top plate of the corner fitting.
ISO 3874 requires that the load-bearing area between a twistlock and a corner casting be a minimum of 800 mm
A number of rulemaking participants, including the Institute of International Container Lessors, the Carriers Container Council, Inc., and the USMX, argued that VTL operations were safe up to a total load of 20 tons and, in that sense, supported the proposal (Exs. 10-4, 10-5, 10-6, 36, 37, 47-2-1, 50-12, 54-1-1, 54-2, 54-3, 65-3). In support of their position that VTLs are safe, two of these commenters stated that they were unaware of any reported injuries resulting from lifting vertically coupled containers (Exs. 10-5, 10-6). For example, the Carriers Container Council, Inc. (Ex. 10-6), said:
The fact that there has not been one reported injury as a result of this practice is evidence that the precautions being applied by terminals performing these lifts are sufficiently protective.
On the other hand, there have been documented VTL events and accidents in the Port of Charleston, South Carolina, in Honolulu, Hawaii, and in Houston, Texas (Exs. 8-A, 11-1-B, 11-1-H, 11-1-K, 11-1-M, 11-3, 11-3-A, 11-3-B, 43-10, 45-1, 61, 62). The International Longshoreman's Association reported that at the Port of Charleston, two 12.2-meter refrigerated containers became uncoupled while in midair (Exs. 8-A, 11-1-B, 11-1-K, 11-1-M, 11-3-A, 11-3-B, 43-10). The ILA also reported two incidents at this port in which the bottom 12.2-meter container of a three-container VTL released in midair (Exs. 11-1-K, 43-10). The ILWU reported two midair separations of the bottom container of two-container lifts in Honolulu, resulting in the lower container crashing to the dock or the deck of the ship, respectively (Exs. 11-1-B, 11-1-H, 43-10, 62). One of these VTLs comprised loaded containers; the other appears to have been empties (Exs. 11-1-H, 62). The ILWU also provided testimony about an event in Canada in which a two-container VTL carrying loaded twistlock bins separated when all four of the twistlocks connecting them broke (Tr. 2-285—2-286, 2-333—2-335).
APM/Maersk reported a VTL separation occurring in Houston while employees were loading a barge with empty containers, in which two twistlocks broke during a l