Value chain · CLM-0984
In plain terms
The programme's own arithmetic for the antenna frame: each beam takes its length divided by five metres a minute plus twenty minutes to handle, which comes to about three hours per bay, padded to four for downtime.
The claim as recorded
NASA's 1981 construction summary derives the MPTS primary frame assembly rate as 4 hours per bay: 104 m and 147 m beams fabricated at 5 m/min plus 20 minutes handling each give 40.8 and 49.4 minutes per beam, 172 and 180.4 minutes per bay for the two beam machines, allowed as 3 hours per bay divided by a 75 per cent productivity factor, using two beam machines and four cherrypickers. The same summary takes equipment rates of 0.5 to 20 m/min as "assumed to be reasonable".
Evidence behind this: T3-programme summary, a derivation shown on one figure.
Scope and limits
ANTENNA PRIMARY FRAME ONLY; THE 20 MINUTES IS THE HUMAN SHARE OF A MACHINE-FABRICATED BEAM, NOT A MANUAL ASSEMBLY RATE. Table III-1 was cited by the text and has not been located and rendered. The 75 per cent productivity factor is ground rule [10] on p.12 (PDF 29), two pages before the rate range: "Construction operations will be performed during two 10-hour shifts per day and at 75 percent efficiency"; it is unexplained on the figure's page only.
What it assumes
The 75 per cent productivity factor is the source's and is unexplained on the page.
Where it comes from
Figure III-39 from the render, "MPTS primary frame assembly equipment, sequence, and time line": "Assembly time: 104 m / 5 m/min + 20 min = 40.8 min; 147 m / 5 m/min + 20 min = 49.4 min; BM 1 3(40.8 min) + 49.4 min = 172 min/bay; BM2 2(40.8 min) + 2(49.4 min) = 180.4 min/bay; therefore allow 3 hr/bay / .75 = 4 hr/bay", with BM = beam machine and CP = cherrypicker, two beam machines (BM1, BM2) and four cherrypickers (CP1 to CP4) named on the sequence. p.12: "Construction equipment rates ranging from 0.5 to 20 m/min, shown in table III-1, are assumed to be reasonable. Low equipment use should be avoided." Arithmetic: 104/5 = 20.8, plus 20 is 40.8; 147/5 = 29.4, plus 20 is 49.4; 3 x 40.8 + 49.4 = 171.8; 2 x 40.8 + 2 x 49.4 = 180.4; 3/0.75 = 4.
Basis: hours per structural bay; beam metres per minute; handling minutes per beam
Related records
- Answers question
- QST-015 not published in this release
Cite this
energyaperture.com/c/clm-0984
CLM-0984, Energy Aperture, as of 1981.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-465
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