# Gregorian weight

#### mar10

Weighing the dome using load cells and jacks.
Weight the dome using motor torques:
jun13: 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 arewith jacks on each of the four corners  or with a load cell liftedfrom the azimuth feed arm top. On the week of Feb  27,2003, thedome was weighed; first, with the jack and then with the load cell, Ishould mention that when the jack's method is used the trolleys areexcluded. In order to determine the trolley's weight, several elementswere weighed during the yoke replacement project and the rest of theweight was calculated. The total weight  obtained for the trolleysbefore the yokes modifications was 17,144 lbs. and after the yokesmodification 19,980 lbs.`
```
As of 2/27/03 (jose's memo had 12/02/98 but i think that was a typo) the dome weightwas 215,390.4 with jacks and 215,660 with load cells. The attachedaddendum A-1 has a break down of Dome weight per corner and a summary ofweight obtained with different methods and different dates. The domewas 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)

 date type Measure Notes corner1 corner2 corner3 corner5 20051024 Corner Weights Jacks without trolley weight 18458uphill left 10521uphill right 76932downhill right 72691downhill 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.
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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