Sometimes elegance takes a backseat

As an engineer I take satisfaction in designing an elegant solution to a problem. Elegance in engineering design is somewhat hard to define. Appearance contributes to elegance but is not essential. Elegance in an engineering sense is developing a solution to a design problem the requires as few components as possible. An elegant solution often has components that serve multiple functions.

A recent project of mine entailed designing an airlock for introducing a sample into a furnace. The furnace operates at 1600 C. The airlock is to prevent introducing air into the furnace chamber. Prior to introducing the sample into the furnace, the airlock is pumped down to a vacuum and then backfilled with inert gas.

My initial design used a thermal shutter just above the furnace to minimize the heat load on the vaccuum gate valve. The thermal shutter was simply a flapper made of refractory material. The vacuum gate valve was a commercial component.

In my search for an elegant solution I thought why not combine the gate valve and thermal shutter into a single unit?

Some reflection provided ample reason not to do this. The gate valve could no longer be a commercial component. It would require active cooling. The most critical requirement would be allowance for thermal expansion. The valve and its seals would have to operate with the furnace temperature ranging from room temperature to 1600 C.

It might have been possible to design a new valve from scratch capable of operating over this range but the design would not have been trivial. Thermal loading and thermal expansion would have to be analyzed.

The project did not have the time or money to design this.

An appaling lack of curiosity

Two years ago I designed the hydraulic system for a large component tester. The unit is driven by a 150 horsepower hydraulic unit. The main hydraulic pumps supply 100 gpm at 2000 psi. All the axes on the unit use hydraulic servo-valves, the largest taking 60 gpm flow. Some of the supply lines are two inches in diameter. The hydraulic system is equipped with air bleed fittings, manual override valves, and manual flush valves.

All in all, a large complicated machine.

This year the customer for whom we built the machine decided to take possession of it, as is their right. It had started out with us running it for them.

The customer informed us that they were sending down an engineer for us to instruct in how to operate and put the machine back together. We, the technical staff thought we would have a week or so to instruct the engineer and that he would be around for the beginning stages of disassembly.

They sent their engineer representative for one day. One day to go over the design, and operation of the mechanical, hydraulic, electrical, and control systems. We were each allotted two hours to provide our bit of instruction. Two hours on mechanical, two hours on hydraulics, two hours on electrical, and two hours on controls.

Two hours! I spent a day a the pump vendor learning how to operate and maintain the hydraulic power unit alone. At the end of that day it felt barely adequate.

On the appointed day at the appointed time I started showing around the engineer. I gave him a copy of the hydraulic design notebook with all the schematics, drawings, and part catalog information for the hydraulic system. I began my part of tour showing him the location of all the manual valves and described for him their function.

He didn't ask any questions.

I was thinking, "I put a lot into this design surely you have some questions! Help me out here. let me know what you want to know."

A half hour into my allotted two hours after showing the location of the manual valves I opened the schematics and asked if he had any questions about the schematics.

"No, no questions," came the response,"It all looks pretty clear."

"You don't have a clue," I thought. How could someone understand and operate something that took months to design? At that point I gave up. Without some interest or curiosity into the design I couldn't begin to instruct him in what he needed to know.

What I said was: "If you have any questions before you leave, I'll be in my office. I will be happy to answer them."

"Thanks, but I think I'm good."

I was appalled both by the presumption shown and the lack of curiosity. The presumption was that the system would be easy to set up. The lack of curiosity was more troubling. There are tradeoffs made in any design. There are reasons, however trivial, for the existence of every part. The engineer could have gained insight into the whys and hows of the design but he showed no interest.