The Size and Shape of Offshore Workers study update Arthur Stewart and Robert Ledingham
The study plan (Dec 2012-Dec 2014) Workpackages 1 + 2 Calibrate the portable scanner against the fixed scanner and quantify error; Determine the optimal protocol for measuring the workforce on 44 individuals Completed November 2013 Workpackage 3 Obtain a representative Sample at least 588 men across 7 weight categories as determined by 2009 VANTAG weight data; Scan each in 7 scans and perform window egress task Completed August 2014 with 667 individuals scanned Workpackage 4 Process each scan (>80% complete) xtract required measures (~10% complete) Develop derived data on full data set Provide these to Oil & Gas UK under agreement for the benefit of the industry (due to be complete end Dec 2014 / Jan 2015)
44 47 50 53 56 59 62 65 68 71 74 77 80 83 86 89 92 95 98 101 104 107 110 113 116 119 122 125 128 131 134 137 140 143 146 149 152 156 Frequenc Study weight categories overlaid on 2009 VANTAG weight Average w eight of m ales travelling offshore in the UK C S 1600 1400 S ample siz e: 44,495 Mean w eight: 90.94kg R ange: 50kg - 158kg # >135kg: 179 (195) 1200 1000 Sample Weight Categories 800 600 400 < 76.4kg 76.5-82.4kg 82.5-87.4kg 87.5-91.4kg 91.5-97.4kg 97.5-104.4kg > 104.5kg 200 Heaviest 1% of offshore workforce 0 W eight (kg)
Data Frequency distribution of body weight (kg) 200 Chart of sample, 150 100 50 C1 0 sample 50 sample 60 sample 70 sample 80 sample 90 sample 100 sample 110 sample 120 sample 130 sample 140 sample 150 sample 160 [Sum of chi^2 = 11.1772; Chi-square critical 19.68 (11df); no significant difference between sample and expected () from the population distribution]
Scans Form fitting Survival suit
Portable 3D scanning Structured light 15 frames per second Real time image registration to construct mask fragments Developed for animations Whole body measurement acquisition 30-45 s Post scan processing ~ 10 minutes
Scans acquired of different masks when scanner views participant from a different perspective Scans registered by identifying recognisable landmarks in each and mapping After experience was gained, it became possible to capture the entire body in a single mask, reducing processing time
Post processing of scan fragments can take 2-10 minutes, and longer if the participant moves significantly.
Initial xtracted Measures Bideltoid breadth (L) Maximum anteriorposterior distance in the sagittal plane across the chest at the deltoid section Maximum anterior-posterior distance in the thorax at the point of greatest anterior extension Deltoid to thorax measurement with one arm elevated stimates of 50 th, 75 th, 95 th, 99 th centiles have been developed, and await full randomised sample to complete.
Technical rror of Measurement as a % of the measurement value Measurement rror TM = (x 2-x 1 ) 2 2n TM is the standard deviation of repeated measurements 2 1.8 1.6 1.4 RL Intratester AS Intratester RL-AS Intertester 1.2 1 Target error 0.8 0.6 0.4 0.2 Sample of 21 individuals analysed separately and blinded 0 Bideltoid Bideltoid depth Thorax depth Deltoid-thorax
Planned measures for extraction Measurement Position Clothing Assemblage 1 Bideltoid breadth gress Form 2 Chest depth at Deltoid transverse plane gress Form 3 Shoulder girth gress Form 4 Maximum thorax depth gress Form 5 Chest Breadth (armpit) Scanner Form 6 Chest Breadth (nipple) Scanner Form 7 Thorax to lateral shoulder Raised arm Form 8 Chest Girth (nipple) Scanner Form 9 Chest Depth gress Form 10 Waist girth minimum Scanner Form 11 Waist girth umbilicus Scanner Form 12 Abdominal depth Scanner Form 13 Hip girth Scanner Form 14 Hip breadth Scanner Form 15 Hip breadth sitting Seated Form 16 Crotch height Scanner Form 17 Neck girth gress Form 18 Wrist girth Scanner Form 19 Buttock to front of knee Seated Form 20 Maximal Breadth gress SSuit 21 Maximal depth gress SSuit 22 Total volume (form) Scanner Form 23 Total volume (SS) Scanner SSuit 24 Abdominal volume Scanner Form 25 Arm volume Scanner Form 26 Leg volume Scanner Form
Approaches to defining space needs Physique method: Using horizontal slices, define the maximum width and breadth i.e. maxima and minima must be in the same plane Box method: Identify the minimum cuboidal box dimensions inside which the participant can fit. i.e. maxima and minima can be in different planes, and this this method is sensitive to posture
48.5 cm 36.0 cm Standing footprint area Male at 129 kg ~ heavier than 99% of workforce Defined as a rectangular space necessary to accommodate a standing person, based on the maximum lateral distance, and the maximal anterior-posterior distance in a sagittal plane 72.3 cm 0.260 m 2 78.7 cm 0.382 m 2 +47%
Questions we will answer What is the size profile of the workforce for each dimension? How well correlated is each dimension to each other and to body weight? What increase in key dimensions have we seen since 1985? What size adjustments are necessary for indoor clothing and survival suit?
Scanning Handbook under development
Future project work with the data Probability testing of size criticality in restricted spaces Forecast modelling for future workforce size Digital composite modelling to produce prototypes which represent average shape Making an adjustment algorithm for key dimensions to convert measures using rebreather to BS Dynamic modelling of movement using real sized individuals
Future Research Needs Size and shape of female offshore workers Compressibility of tissue and clothing Shoulder flexibility and emergency egress Comfort of seat size and space in relation to body shape