The EAND Papers – No.2: A Mild Case of Mill Ennui

There has been one useful side effect of writing these little articles on LinkedIn.

They sometimes feel futile. I write them, fiddle with them, question their value, decide no one will read them, then keep going anyway. This is not an efficient process. It is, however, familiar.

The real value is that it has got me drafting technical journal papers again.

The old researcher from the 1980s is still in there somewhere, still trying to pull another useful idea out of strain gauges, vibration traces, mill drawings, shell stresses, liner loads and the lessons other people would rather call “learnings”.

I am suffering from a mild case of mill ennui.

Not because grinding mills are boring.

They are not.

A grinding mill is a large steel animal. It sits on bearings, eats rock, steel balls and electrical power, and occasionally expresses itself through cracks, vibration, fretting, bolt failures, hot drives, strange noises and photographs taken by worried people on site.

A mill is still interesting.

The ceremony around the mill is the tiring part.

There is always a meeting.

Then there is a meeting to prepare for the meeting.

Then there are minutes, action items, document registers, carefully worded responsibilities, approvals, clarifications, qualifications, standard terms, revised standard terms, and finally a meeting to confirm that the previous meeting was “aligned”.

Somewhere underneath all of this, there is usually a piece of steel trying to say something simple.

“I am cracking.”

“I am bending.”

“I do not fit.”

“I am not loaded the way someone assumed.”

“I am about to make everyone’s week worse.”

Steel is wonderfully direct. It has not been to a communications workshop.

People, however, have.

So a crack is not always called a crack.

A crack can become a “local discontinuity requiring assessment”.

If that is still too direct, it can become … “premature segmentation”.

If a casting should be rejected, one must be careful. “Rejected” can sound offensive. The casting may feel judged. So perhaps it is “not yet aligned with the acceptance pathway”.

If a foundation vibrates, one might say “the foundation is showing unexpected enthusiasm”.

If a site fix may break the part, one can say “the proposed installation method appears to rely on optimism as a temporary mandrel”.

This is how engineering becomes safe for meetings.

Can we fix the problem by rewording the problem?

Often, no.

But we can make the problem sound less rude while it continues to exist.

Reality is impolite in this regard.

Reality does not come to meetings.

Reality does not wait for the minutes.

Reality does not care whether the word “reject” was softened.

Reality simply turns up later with photographs.

That is usually when the language becomes more direct.

A failed drive does not say, “I note the maintenance team’s preference for scheduled maintenance.”

A broken casting does not say, “I accept that all parties acted in good faith.”

A cracked mill shell does not say, “I understand the commercial sensitivity.”

It just cracks.

This is why old engineers become difficult. They have seen the polite version before. They have seen a difficult fact softened until it became harmless. They have seen the assumption that survived every meeting and died on site. They have seen the inconvenient reviewer treated as the problem because he found the problem before the problem became expensive enough to be undeniable.

There is also the matter of calculation.

Sometimes the old methods still matter.

Getting a useful estimate of mill load distribution from one strain gauge rosette is close to magic. Not stage magic. Not rabbits and hats. Engineering magic. The magic of listening to John Simmons in E4349 Linear Systems in 1978 and 48 years later realising, to your surprise, that the lecture was not merely something to survive before lunch.

A mill shell, one gauge, a rotating structure, a set of loads you cannot see directly, and a problem that is badly behaved if you ask it the wrong question.

That is interesting.

That is still interesting.

There are days when I think I am finished with all of it. I look at the dogs waiting to go for a walk, the cameras waiting to take photos, the snooker table waiting to embarrass me, and I think that perhaps the world has enough mill engineers.

Then someone says:

“Our foundation is vibrating.”

Or:

“The casting almost fits.”

Or:

“The crack is only local.”

Or:

“This is industry standard”

And the old reflex returns.

Not enthusiasm exactly.

More like professional suspicion with a pulse.

I lean forward.

I start wondering where the load path really goes.

I wonder what was assumed.

I wonder what was measured.

I wonder whether the angels dancing on the head of the pin were meshed with solid elements or shell elements.

I wonder whether a strain gauge, used properly, may tell us more than a confident explanation used to end a discussion.

This is the annoying thing about mills.

Just when I think I am tired of them, they become interesting again.

Perhaps that is not ennui.

Perhaps it is just the normal condition of an old engineer who has seen enough projects to be tired of the performance, but not yet tired of machines.

The projects come and go.

Clever warranty clauses come and go.

The meetings multiply.

The language softens.

Then, the photographs arrive.

And somewhere in the middle of it all, a large rotating piece of steel keeps asking the same rude question:

“Why did you design me like this? It hurts!”