[Hallb-engineering] Fwd: Lesson Learned "ACC-16-0303- Shoulder Injury During Disassembly Task"
tilles at jlab.org
Thu Jul 14 13:27:06 EDT 2016
----- Forwarded Message -----
From: "Tina Johnson" <cjohnson at jlab.org>
To: "Tina Johnson" <cjohnson at jlab.org>
Sent: Wednesday, July 13, 2016 12:00:17 PM
Subject: Lesson Learned "ACC-16-0303- Shoulder Injury During Disassembly Task"
Jefferson Lab Lessons Learned : Print Lesson
ACC-16-0303- Shoulder Injury During Disassembly Task
Statement of Lessons Learned
1. Employee became discouraged when they failed to receive feedback from their supervisor with regards to the status of previously identified concerns. The employee further became reluctant to provide additional concerns to their supervision with the idea that they too would not be addressed. In reality, the previously identified concerns were being addressed by the supervisor and management, but incomplete feedback from the management led the employee to believe they were not being addressed.
To promote an atmosphere of inclusiveness and enhance overall employee engagement, and to encourage continued feedback within the organization, it is important to close the loop with personnel so they know their feedback is being handled, even if progress is slow.
2. During scope creep, it is important to reassess and ensure correct work planning and control is implemented before work continues. New hazards can be introduced during scope creep and without stopping to reassess the situation, any unmitigated hazards could cause unwanted consequences.
Always stop and reassess scope creep to ensure all hazards are mitigated before continuing.
3. Always review tool usage during job specific hazard analysis to ensure worker safety. Ensure the right tool is on hand at the time of task performance and reassess hazards for any tool substitution before continuing work.
Discussion of Activities
On March 3rd, 2016 at approximately 11am in the morning, a worker while attempting to loosen bolts on hardware attached to a 9-cell cryomodule cavity felt and heard an audible pop in their shoulder. They did not think anything of the incident and continued working. Over the weekend, the symptom of pain in shoulder did not go away and Employee #1 reported the incident to their supervisor the following Monday during a toolbox meeting. Employee #1 was evaluated by OccMed on Wednesday when the doctor was available.
Process changes were made in order to ensure the quality of processed cavities but without fully reevaluating all tasks for additional hazards associated with the changes.
A change was made in historical process steps to keep the cavity in a vertical orientation after cavities are processed. Due to this change in process, disassembly tasks normally carried out in a horizontal orientation, which is more ergonomically friendly for both ends of the cavity, now needed to be carried out above the worker's head and below their knees. Workers used a step ladder to gain better access to the bolt pattern above their heads and kneeled for the bolts below their knees, but used methods which were not ergonomically sound and an employee was injured. While the methods used in the task were cursory evaluated by the supervisor and thought to be satisfactory, the job was not fully evaluated for all hazards prior to execution due in part to a lack of understanding in what to look for.
In addition to the orientation change, another process change was made in an effort to keep the quality of cavity processing at a high level. Assembly Techs who normally would disassemble the cavities were asked to forward the cavities to the Chemical Techs for processing and disassembly. During the investigation, it was noted that while disassembly tasks were similar to other disassembly tasks Chemical Techs provide on a routine basis, the Chemical Techs were not used to the process of disassembling cavities with torqued bolts or while it was in a vertical orientation. It was also noted that different levels of physical capabilities between the work groups may have played a part in the incident.
Management believed that no variability existed in the new process steps and overlooked the fact that a change had occurred leading to differing results than normally realized. These changes were not fully evaluated to see if the different process steps added additional hazards.
DOE Cause Code:
A3B3C04 - LTA Review Based on Assumption that Process Will Not Change
Along with the Root Cause, several Contributing Causes (or Causal Factors) were identified during the causal analysis and are described below.
The Direct Cause of the incident was due to the Ergonomics being Less Than Adequate (LTA.) The worker manipulated a wrench in an awkward position due to the fixture height, the motion needed to free the nut/bolt from its torqued configuration and the fact that there was a change in process which mandated having the cavity oriented in an upright position versus the historic and more accessible horizontal plane. The orientation and motion to free the bolts were not ergonomically sound and the worker was injured during the process step.
A contributing factor was that Employee #1 underestimated the problem based on evidence of success from a previous event. At least two cavities had recently been disassembled with the same tools without incident. When Employee #2 experienced problems while attempting to unbolt the cavity from the fixture, Employee #1 attempted to unbolt the cavity using the same tools without considering the evidence from Employee #2's failure and possible physical limitations of Employee #1 before proceeding based on the prior success.
Another contributing factor to the event was the job scoping did not identify special circumstances and/or conditions that exist due to alterations to historic task performance. Previously, cavities could be manipulated into an orientation to allow ease of assembly/disassembly. However, recent requests were made to ensure cavity processing quality by keeping the cavity oriented in an upright position versus the historic horizontal and ergonomically friendly orientation. Because the cavity had to be held in an upright position, the normal disassembly tasks were made more difficult due to the creation of awkward angles of the task that did not exist before.
Improper tool selection used for the task was based on previous success with the same tools by another employee during an identical task.
Work plan did not adequately account for all off normal activities and this causal factor is related to the Root Cause:
- Assembly Techs usually carry out disassembly tasks on cavities. An updated process put the disassembly tasks in the hands of the acid techs to reduce the risk of contamination after processing if sent back to the Assembly Techs.
- Cavities needed to be held upright to meet proper processing requirements. Unfortunately, this orientation made it difficult to access all flanges needing disassembly and the ergonomics for this task in the requested orientation was not properly assessed or mitigated prior to task performance.
DOE Cause Codes:
A1B5C01 - Ergonomics LTA [DIRECT CAUSE]
A3B3C06 - Individual underestimated the problem by using past event as basis
A4B3C08 - Job scoping did not identify special circumstances and/or conditions
A4B5C10 - Change-related equipment not developed or revised
1. Safety Observation of Production Room bench chemistry activities and provide report to SRF Chemical management for consideration.
2. Investigate alternatives to Production Chemistry Room task execution and fixtures based on Safety Observation Report.
3. Ergonomic Assessment of Production Chemistry standard and abnormal tasks.
4. Work with ES&H on ergonomic overview training for supervisors to assist them in recognizing ergonomic issues needing SME review.
JLab Preventive Measures
7/13/2016 10:45:29 AM by Johnson, Tina
Please share within your work group.
Summary Lesson ID: 956
Safety Related: NO
Originator: Johnson, Tina
Issued: 7/13/2016 10:31:55 AM
Approved By: Johnson, Tina
Approved On: 7/13/2016 10:45:29 AM
Source: TJNAF NE
Contact: Harry Fanning
Queued Emails: 0
Sent Emails: 0
Viewings: 2 times Attachments
* Ergonomics - Lifting, Carrying, Repetitive Motion
* Portable Hand Tools
* *Division Safety Officers (DSOs)
* *Safety Wardens
* *DOE Notification
* *ESH&Q Liaisons
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