MEMO
From: The Boss of the comapany
Subject: New Internet Cable Tension Machineinstallation Issue
Action: Your recommendation with detailedanalysis and guidelines are required.
HINT: The question is worded like a businessmanwould write to you. There is more information than you need, ignorethe fluff and focus on the objective. You should be able to do thisin 10 minutes.
I received an urgent call this afternoon from our senior fieldservice team leader Chuck R onboard the Japanese vessel K1. Thevessel is dedicated to Internet cable installation in the ocean.This field service team is currently in charge of the installationof our new tension machine onboard the vessel. Chuck has indicatedthat they are in the final testing stage for our customer finalacceptance test of the entire system. He is very stressed becausethis final acceptance test approval is tied to about $2.5 Milliondollars payment. He needs our support.
Chuck has indicated to me that during the final test, the systemcomputer screen (AKA Man Machine Interface, MMI) that is connectedto the system controller that displays all the system parameters tothe operators, indicates the correct tension up to the maximumrating of the machine of 100 KIP and was calibrated to this rating.The system controller has a 12-bit ADC resolution. However, whenthe system testing exceeds the machine rating, the MMI displayscrazy tension numbers. Normally, the system MMI should display 1KIP resolution.
In addition, Chuck told me that our new programmer on the team,Roger has diagnosed the problem and indicated that the load cellsneeds to be upgraded to higher capacity load cells. This is ofcourse a showstopper. New load cells units cost only about $5000,but the helicopter cost is about $60,000. Chuck is not sure aboutthe electronics and the digital issues but he thinks that noadditional mechanical engineering or manufacturing is needed incase we decide to upgrade. We still need to check with the entireengineering group. However, he is sure that each load cell isconnected to a signal conditioning electronic card that outputs0-10 DC volt to the system ADC. Each card has adjustable knobs, onefor zero percent and the other for span (100%).
As you know we are all off for the holidays next week, however Iwill dispatch the entire engineering group back to the office if Ihave to, but I need your analysis before I do that since you’re theonly engineer on the premises today.
Chuck also indicated that Roger told the customer to apply 0-100KIP force on the machine while he was calibrating the controllerprogram to display the correct reading.
Our tension machine capacity is rated at 100KIP. However, ourmechanical and manufacture design has 200% safety margin, we mustnot operate at that upper limit of course, but we should be able tooperate and display above the machine rating within a reasonablelimit. Our standard is twenty percent above the rating.
FYI, the machine has two load cells (SPWE-CA-50K) installed tomeasure the total tension. One installed on the starboard side andthe second installed on the port side of the machine. Their totalreadings represent the total tension on the machine.
I included the load cell manufacture link below.
I need your recommendation with detailed analysis andguidelines to the field service team.
https://www.800loadcel.com/load-cells/pancake-shear-web-load-cells/spwe.html
