October 1, 2022 Fatality – Final Report
Accident Report: Fatality Reference
October 1, 2022 Fatality
PDF VERSIONOCTOBER 1, 2022 – FINAL REPORT .PDF (642.01 KB)
FAI-6923436-1UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATIONREPORT OF INVESTIGATION
Surface
(Crushed, Broken Limestone)Fatal Machinery Accident
October 1, 2022R J Valente Grafton Quarry
R J Valente Gravel
Grafton, Rensselaer County, New York
ID No. 30-03434Accident Investigators
Daniel Pullen
Mine Safety and Health InspectorMichael Powers
Mine Safety and Health InspectorOriginating Office
Mine Safety and Health Administration
Warrendale District
178 Thorn Hill Road, Suite 100
Warrendale, PA 15086
Peter Montali, District ManagerOVERVIEW
On October 1, 2022, at 8:13 a.m., Darren Miller, a 35 year-old mechanic with over 47 weeks of mining experience, died when he was struck by the overhaul hook ball on a crane. The crane was being used to install an engine and transmission in a haul truck when the overhaul hook ball detached and fell.
The accident occurred because the mine operator did not: 1) ensure that the mechanic stayed clear of suspended loads while replacing the engine in the haul truck, and 2) remove the crane from service to prevent operation in an unsafe manner.
GENERAL INFORMATION
R J Valente Gravel owns and operates the R J Valente Grafton Quarry, a surface limestone mine located in Grafton, Rensselaer County, New York. R J Valente Grafton Quarry employs 12 miners and operates one ten-hour shift per day, five days per week, and a half shift on Saturdays. The mine loads, hauls, and processes limestone from the quarry, and loads customer trucks with the final product.
The principal management officials at R J Valente Grafton Quarry at the time of the accident were:
Anthony Valente Manager
Bryan Ostrander Operations ManagerThe Mine Safety and Health Administration (MSHA) completed the last regular safety and health inspection at this mine on July 7, 2022. The 2021 non-fatal days lost incident rate for R J Valente Grafton Quarry was 9.28, compared to the national average of 1.26 for mines of this type.
DESCRIPTION OF THE ACCIDENT
On October 1, 2022, at 7:00 a.m., Anthony Valente (Valente) and Darren Miller arrived at the mine site and began preparations to install the engine and transmission into the haul truck. At 7:09 a.m., Valente started the crane while Miller connected the crane’s rigging to the engine. At 7:26 a.m., Valente activated the Load Moment Indicator (LMI) system override to bypass the safety system. The LMI system monitors various sensors, interprets the crane’s changing configuration during a lift, and provides the crane operator with a continuous reading of the safe operating capacity.
Miller initially guided Valente’s movement of the crane using hand signals from the ground. Valente lifted the engine from a trailer and moved it to the front of the truck. Guided by Miller’s signals, Valente raised the engine and moved it slowly into place. When the engine was above the truck’s engine compartment, Miller climbed up onto the truck frame behind the engine compartment. Valente raised the engine again to align it with the engine mounts. Valente stated that on at least two occasions, he increased the slack on the auxiliary line to avoid pulling the ball into the sheave. At one point, Miller yelled, “we’re almost there.”
Miller gave Valente the hand signal to move the crane’s boom. When Valente made this adjustment, the overhaul hook ball was pulled up into the sheave, which severed the hoist rope. The overhaul hook ball fell and struck Miller. At 7:55 a.m., Valente called to Miller and received no response. Valente turned off the crane, exited the crane, observed Miller’s condition, and ran to Ostrander to inform him of the accident.
At 8:03 a.m., Ostrander called 911. Grafton Fire Company, Inc and New York State Police were dispatched and arrived within minutes. Eric Cullum, Medical Legal Death Investigator for Rensselaer County, pronounced Miller dead at 8:13 a.m.
INVESTIGATION OF THE ACCIDENT
At 8:11 a.m., Ostrander called the Department of Labor National Contact Center (DOLNCC) to report the accident. The DOLNCC contacted Thomas Rasmussen, Staff Assistant. Rasmussen contacted, Brian Righi, Supervisory Mine Safety and Health Inspector, who called Ostrander and issued an order under the provisions of Section 103(j) of the Mine Act to ensure the safety of the miners and preservation of evidence. Righi sent Matthew Mattison, Mine Safety and Health Inspector, to the mine. At 10:10 a.m., Mattison arrived at the mine and modified the 103(j) order to a 103(k) order. Andrew Bower, Supervisory Mine Safety and Health Inspector, sent Daniel Pullen and Michael Powers, Mine Safety and Health Inspectors, to the mine and assigned them to lead the investigation.
At 2:15 p.m., Pullen and Powers arrived at the mine to conduct the investigation. MSHA’s accident investigation team conducted an examination of the accident scene, interviewed miners and mine management, and reviewed conditions and work procedures relevant to the accident. See Appendix A for a list of persons who participated in the investigation.
DISCUSSION
Location of the Accident
The accident occurred on Level 3 of the quarry (see Appendix B).Weather
The weather at the time of the accident was 50 degrees Fahrenheit with mostly sunny skies and a light breeze. Investigators determined that weather did not contribute to the accident.Equipment Involved
The haul truck involved in the accident was a Caterpillar 773B haul truck. Investigators found the crane’s overhaul hook ball sitting on the frame of the haul truck. Based on interviews, investigators determined that Miller was standing on the haul truck’s frame where the overhaul hook ball was found at the time of the accident. Investigators also determined that the haul truck did not have any defects that contributed to the accident.The crane involved in the accident was a 2016 Grove RT765E-2 rubber-tired crane with a rated lifting capacity of 65 tons. The crane had two hoists, one main and one auxiliary. The main hoist had a load block lifting system that used pulleys to increase capacity for lifting heavier loads. The auxiliary hoist had an overhaul hook ball lifting system and was typically used for lighter loads when speed is more critical than weight capacity.
According to interviews, the crane was brought to the mine in April 2020 as a rental unit. While returning the crane to the rental company on April 21, 2020, the crane was damaged when it rolled over during the transportation process. The mine operator purchased and repaired the damaged crane. After the repairs were made, the crane was not certified or inspected by the manufacturer or a manufacturer’s representative for use after the rollover incident. Manitowoc Crane Care sent a letter to R J Valente Gravel on January 21, 2021, stating that the damage to the crane meant it was not fit for service and that they would work with the crane’s owner to ensure that the crane could be properly repaired and inspected afterward. Based on interviews, investigators learned that the crane was used at the mine soon after the mine operator made repairs. Additionally, the auxiliary wire rope hoist line on the crane was damaged in May 2022 and was defective at the time of the accident. During the four previous regular inspections conducted by MSHA, from February 2021 through July 2022, the crane was documented as “tagged out of service” and the crane received only a visual inspection.
Two-Blocking
Two-blocking is an unsafe condition where the crane’s suspended load or loading attachments contact the sheaves at the end of the crane’s boom (Appendix C). This can occur by raising the hoist past its upper limits or by telescoping the crane boom without releasing enough hoist line to compensate for the additional boom length. Two-blocking can cause damage to the hoist line and sheaves because the hydraulic power of the crane can exceed the material strength of these components. Failure of the hoist line causes the suspended load to fall.The crane had an anti-two-blocking system consisting of two limit switches, a junction box, a signal cable, a cable reel, and a control system. The signals from the two limit switches combine in the junction box and relay through the signal cable into the cable reel that is on the side of the boom. The cable reel sends the limit switch signals to the control system in the operator’s cab. The LMI system is part of the control system.
On October 3, 2022, Mark Kvitkovich and Jennifer Okpala, Mechanical Engineers with MSHA Technical Support (TS), and Roland Laxton, Technician for Stephenson Equipment, Inc., arrived at the mine to evaluate the crane and found multiple safety defects. On November 9, 2022, Darrick Marris, Vice President for Stephenson Equipment, Inc., and Eric Fidler, Director, Product Safety for Manitowoc Company, Inc., arrived at the mine site to assist TS investigators in their evaluation of the crane. Investigators obtained the saved electronic data stored in the control system of the crane (see Appendix D).
As part of the anti-two-blocking system, each hoist on the crane has a limit switch with a ten-pound weight attached to the hoist line above the suspended load. When the weight contacts the limit switch, the control system recognizes a two-blocking fault and stops the hydraulic hoist motor. This is designed to prevent the load from being raised any further. MSHA TS investigators did not find visual evidence of damage to the main hoist limit switch assembly but found damage to the auxiliary hoist limit switch assembly. Additionally, the weight was laying on the deck of the crane with damaged mounting hardware. This damage would not have allowed reattachment of this weight to the limit switch to function properly. Furthermore, the sheave on the end of the auxiliary hoist boom had paint transfer marks from the overhaul hook ball assembly, indicating that two-blocking had occurred. According to interviews, Valente frequently pulled the overhaul hook ball into the sheave on the end of the auxiliary hoist boom while operating the crane.
Another component of the anti-two-blocking system was the slip ring conductor. The cable reel used the slip ring conductor to maintain the electrical connection between the limit switches on the end of the boom and the control system in the operator’s cab. MSHA TS investigators found the slip ring conductor dislodged, damaged, and laying inside the cable reel housing. The condition of the slip ring conductor caused the crane’s control system to signal a two-blocking fault that limited the operation of the crane.
MSHA TS investigators determined that the only way to operate the crane was to bypass the anti-two-blocking system by activating the LMI system override function. The LMI system override switch was in the operator’s compartment and activated by a key. The mine operator kept the key in the crane. The crane was operated in an override mode because the control module was continuously giving an error which caused a flashing light alarm and an audible alarm to prevent operation of the crane. The crane operator had to turn and hold the key switch in the “On” position to activate the override function and turn off the alarm. The spring return key switch returned to the “Off” position when the crane operator released the key. The use of this override function by the crane operator allowed the crane to operate in an unsafe manner, which contributed to the accident. According to interviews, the anti-two-blocking system had not functioned during 2022 and the crane was always operated in the override mode. According to the data recorded by the crane, the LMI system override function was used 32 times between August 20, 2022, and October 1, 2022.
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October 1, 2022 Fatality – Final Report | Mine Safety and Health Administration (MSHA)
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