A Universal Rig for Supporting Large Hammer Drills: Reduced Injury Risk and Improved Productivity

Design and evaluation of a feed handle for a bench drilling machine

BACKGROUND: Despite extensive industrial use, no major modifications to the bench drilling machine, with respect to ease of operation, have been undertaken. OBJECTIVE: The objectives of the study were to design a new feed handle (NFH) to perform the drilling task on a bench drilling machine and evaluate the existing (EFH) and new feed handles on the basis of performance measures like drilling productivity in terms of metal removal rate (MRR) and worker performance in terms of perceived discomfort score (PDS). METHODS: Participants performed the drilling task on a steel block for three different working durations at two drilling speeds. RESULTS: ANOVA analysis carried out for the MRR data showed that drilling speed had a statistically significant effect on the task performance of the operator for both handles. However, the task duration was found to be statistically significant only for the EFH. The ANOVA results obtained on the PDS data showed that the task duration and drilling speed had a statistically significant effect on the task performance of the operator for both systems. CONCLUSIONS: The MRR obtained was higher when the drilling task was carried out using NFH. An appreciable decrease in PDS was also observed using the proposed system.

Building a Sustainable Construction Workforce

The average U.S. construction worker is aged 42.6 years, and will not be eligible for full Social Security retirement benefits until age 67. Delayed retirement is largely driven by economic need, but construction workers face considerable challenges in remaining on the job. This study explores trade-specific age trends within the construction industry, and the experiences of building trade unions with aging membership. A mixed-methods approach used trade-specific age statistics from the Current Population Survey and key informant interviews with labor leaders, in order to identify union experiences and interventions. Mean and median ages for all subgroups in construction increased from 2003 to 2017. Immigrant construction workers were significantly younger than workers who were born in the U.S. (41 vs. 43, p < 0.001). Union workers were older than non-union workers (42 vs. 39 in 2017, p < 0.001); the age differential between self-employed and wage-and-salary workers was wide (49 vs. 40, p < 0.001). Union leaders described barriers, such as age discrimination and the loss of previously available light tasks, as well as current and potential solutions through union contract language requiring the inclusion of older workers, or establishing limits for lifting. Other solutions included career pathways for training and safety, with their attendant limitations; mentoring/pairing opportunities with apprentices; and the potential opportunities and training needs for site management positions.

A New Test Bench System for Hammer Drills: Validation for Handle Vibration

Workers' can be exposed to high levels of hand vibration when drilling into concrete or rock using hammer drills; exposures that can cause hand arm vibration syndrome. Exposure levels may be reduced by different drill and bit designs and drilling methods, but these interventions have not been systematically evaluated. The purpose of this project was to develop a robotic test bench system for measuring handle vibration on drills in order to compare differences in drill designs, power sources, bit designs and drilling methods. The test bench is a departure from the ISO method for measuring drill handle vibration (ISO 28927-10), which requires drilling by humans. The test bench system was designed to repeatedly drill into concrete blocks under force control while productivity and handle vibration were measured. Handle vibration levels with different drills and bit sizes were similar to those collected following ISO methods. A new robotic test bench system for measuring handle vibration is presented and validated against ISO methods and demonstrates dynamic properties similar to human drilling.

Predicted endurance times during overhead work: influences of duty cycle and tool mass estimated using perceived discomfort

A need for overhead work remains in several industries and such work is an important risk factor for shoulder musculoskeletal problems. In this study, we evaluated the effects of duty cycle and tool mass on endurance times during overhead work. A psychophysical approach was used, via a new methodology that was implemented to more efficiently estimate endurance times (rather than through direct measurements). Participants performed a simulated overhead task in specified combinations of tool mass and duty cycle. Both duty cycle and tool mass have substantial effects on the development of fatigue and estimated endurance times, though the former was more substantial and an interactive effect was evident. Gender differences were not substantial, except when using the largest tool mass. We recommend that, for two-hour periods of overhead work, tool masses greater than 1.25 kg should be avoided, as should duty cycles greater than 50%. Practitioner Summary: The current results may facilitate enhanced design and evaluation of overhead work tasks. In addition, the new estimation approach that was employed may enhance the efficiency of future studies using a psychophysical approach (ie using extrapolation of patterns of reported discomfort to predict longer term outcomes).

Baby boomers in the United States: Factors associated with working longer and delaying retirement

OBJECTIVES

This study estimated the self-reported probability of working full-time past age 62 (P62) or age 65 (P65) among four cohorts of Americans born between 1931 and 1959.

METHODS

Data from the Health and Retirement Study (HRS) were analyzed. Respondents in four age cohorts were selected for comparison. Multivariable linear regression models were used to assess cohort differences in P62 and P65 while adjusting for covariates.

RESULTS

P62 and P65 increased among boomers despite worsened self-rated health compared to the two preceding cohorts, with 37% and 80% increases among mid-boomers in construction trades. Cohort differences in P62 and P65 remained after controlling for covariates. Changes in pensions, income inequity, and education were significantly associated with work expectations, but SSA policy was not.

CONCLUSIONS

Baby boomers expect to work longer than their predecessors. Efforts to improve work quality and availability for older workers are urgently needed, particularly in physically demanding occupations. Am. J. Ind. Med. 60:315-328, 2017. © 2017 Wiley Periodicals, Inc.