Gregorian weight

mar10

Weighing the dome using load cells and jacks.
Weight the dome using motor torques:
jun12: after the hydraulic brake was installed
25jun02:Weighing the dome using motor torques.
Summary

Intro

The gregorian dome has been weighed using the following techniques:

Jacking each corner of the dome and measuring the jack pressure.
Lifting the dome from a beam suspended from the top chord of the azimuth arm and then reading the loadcell tension.
Driving the dome uphill then down hill at different velocities and then using the motor torques to compute the dome weight.

Weighing the dome. dec98,feb03,oct05

Below is jose Maldonado's 28mar03 dome weight memo:

The dome weight could be weighed by two different methods. These are
with jacks on each of the four corners  or with a load cell lifted
from the azimuth feed arm top. On the week of Feb  27,2003, the
dome was weighed; first, with the jack and then with the load cell, I
should mention that when the jack's method is used the trolleys are
excluded. In order to determine the trolley's weight, several elements
were weighed during the yoke replacement project and the rest of the
weight was calculated. The total weight  obtained for the trolleys
before the yokes modifications was 17,144 lbs. and after the yokes
modification 19,980 lbs.



    As of 2/27/03 (jose's memo had 12/02/98 but i think that was a typo) the dome weight
was 215,390.4 with jacks and 215,660 with load cells. The attached
addendum A-1 has a break down of Dome weight per corner and a summary of
weight obtained with different methods and different dates. The dome
was at 1.05 degrees all day long during the measurements.



    On 12/2/98 the dome weight with the jacks became
156,075 lbs. On 2/27/03 five (5) years later the weight from 12/2/98 to
2/27/03 is 59,315 lbs and the dome weight is 215,660 lbs.

Jose maldonado's oct05 dome weight memo (.pdf)

Weighing the dome with jacks and load cells
date	type	Measure	Notes	corner1	corner2	corner3	corner5
20051024	Corner Weights	Jacks	without trolley weight	18458 uphill left	10521 uphill right	76932 downhill right	72691 downhill left
			with trolley weight (4995/corner)	23453	15516	81927	77686
				Uphill		Downhill
	Uphill/ downhill totals			38969.0		159613.
	total			198582

2/27/03	Corner Weights	Jacks	without trolley weight	18,768	19,872	79,488	77,280
			with trolley weight (4995.6/corner)	23764	24868	84484	82276
		load cell	includes trolley weight	34980	13060	85860	81760
				Uphill		Downhill
	Uphill/ downhill totals	Jacks		48631		166759
		load cell		48040		167620
	Total	Jacks		215390
		load cell		215660

12/02/98	Corner Weights	Jacks	without trolley weight	16305	6581	62418	53628
			with trolley weight (4286/corner)	20590	10867	55704	57914
				Uphill		Downhill
	Uphill/ downhill totals			31457		124618
	Total			156075

Notes:

feb03 load cell, jacks agree pretty well except for the corner 1,2 individual measurements.
I also have a note that 24jul03 there is a dome weight measurement:

dome:170,000 no trolleys
trolley: 20,000
total: 190,000 (no pigs)
Need to find out which measurement this was.

Weighing the dome using the motor torques:

jun13: weight the dome using uphill motor torques (after the hydraulic brake)

The hydraulic brake was installed in jun02 on the dome. Fits were done for torques moving uphill. One of the fit parameters was the dome weight.(dome weight)

25jun02: Weighing the dome using motor torques (before the hydraulic brake)

On 25jun02 the dome was driven uphill and downhill at different velocities. The motor torques need to do this were recorded and then used to compute the dome weight. This was done before the hydraulic brake system was installed on the dome.

Dome weight from motor torques: 208000 lbs.

processing: x101/Y02/020621/doitgr.pro

Summary:

Date	Measurement	Dome Weight (including trolleys) (kips)
02dec98	Jacking the dome	156075
25jun02	Gregorian motor torques	208,000
27feb03	jacking the dome	215390
27feb03	load cells lifting the dome	215660

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