Waddington Effect

[docc]

A car enthusiast in the family passed along several magazines published by the Hagerty Classic Car Insurance Company. (They insure classic motorcycles as well.)  I've been really enjoying the articles and features (Jay Leno writes for them and I've always enjoyed his motor-headed perspective).

In the Nov/Dec 2018 issue, I ran across a piece by journalist, Aaron Robinson, referencing the "Waddington Effect" which discovered WWII British bombers suffered increased reliability problems after their scheduled inspection/maintenance. While I have observed this in motorcycling and other road vehicles, I felt reassured that others have also found this to be real. More support for my reluctance to take anything else apart on the Sport before the South'n Spine Raid in six weeks. 

( I want to earn my  "  "  back!  )

Those of you in aviation, marine, and other fleet maintenance may have heard of Waddington, but this is my first exposure and his findings ring true with my experience, especially that of my recent wheel bearing failure.

A couple summary quotes to kick off the discussion:

“The rate of failure or repair is highest just after an inspection and thereafter falls,

becoming constant after about 40-50 flying hours.”    - CH Waddington

 

“But the fact is that the inspection tends to increase breakdowns,

and this can only be because it is doing positive harm by disturbing a reasonably satisfactory state of affairs.” - CH Waddington

 

“It was as if the old parts were jealous of the new parts and chose to ruin it for everyone.” - Peter Darragh, Mariner-USA

 

 

[MartyNZ]

It is called "infant mortality" nowadays, and is a consideration in a "reliability centred maintenance program". It's not the whole story, but the effect is real.

https://blog.aopa.org/aopa/2014/02/11/roots-of-rcm/  

[andy york]

Mr Waddington must have had a sister that married a Murphy. 

 

[luhbo]

Never. The Murphys already had emigrated to Italy those days

[LowRyter]

It's usually the case that once an aircraft has been overhauled in the depot, that is takes a shakedown to be returned to user and then gets fitted for return to service. 

[MartyNZ]

The Waddington Effect sounds a bit like the story about Mrs Schilling's orifice.

She developed a way to allow the early Solex carburettor equipped Rolls Royce Merlin engines to run inverted for longer. I suspect that my bike won't run inverted either. Do I need Beatrice's help?

https://www.open.edu/openlearn/science-maths-technology/engineering-technology/beatrice-shilling-1909-1990#

[docc]

Our kinda lady, it seems!  . . . .

‘Her idea of relaxation was to drive a fast car at full throttle,

and if the car was not fast enough, her workbench was there in the back room to machine new parts to make them faster.’

[docc]

Once again: I am six weeks to the (Seventeenth) South'n SpineRaid and I am flirting with the Waddington Effect. Determined to seal leaks from my gearbox preselector plate, I removed it last week (and installed a roller bearing on the "indexer" arm). A circlip failed to capture and the Neutral Switch failed (Waddington!!) on a 207 mile shakedown ride. (Otherwise, shifted fabulously!)

That is corrected today, but required the preselector to be removed and reinstalled/ resealed.

My question: Since there was an additional service procedure, does the "Waddington Clock" get reset?

Another ten hours of  operation to re-establish reliability/ "roadworthiness"?

[andy york]

Only in YOUR mind. !

[Tomchri]

27 minutes ago, docc said:

Once again: I am six weeks to the (Seventeenth) South'n SpineRaid and I am flirting with the Waddington Effect. Determined to seal leaks from my gearbox preselector plate, I removed it last week (and installed a roller bearing on the "indexer" arm). A circlip failed to capture and the Neutral Switch failed (Waddington!!) on a 207 mile shakedown ride. (Otherwise, shifted fabulously!)

That is corrected today, but required the preselector to be removed and reinstalled/ resealed.

My question: Since there was an additional service procedure, does the "Waddington Clock" get reset?

Another ten hours of  operation to re-establish reliability/ "roadworthiness"?

Docc, don’t worry about the clock, reset or not, W affects or not. Quit wearing watches 30+ years ago. Take care of the gal, and think about the 6000 rpm song. .

 Cheers tom

[docc]

Yeah, it's all dos-y-dos until the single point of failure. I don't want to be That Guy. Again.

[p6x]

On 7/24/2019 at 2:46 AM, MartyNZ said:

It is called "infant mortality" nowadays, and is a consideration in a "reliability centred maintenance program". It's not the whole story, but the effect is real.

https://blog.aopa.org/aopa/2014/02/11/roots-of-rcm/  

In one of my line of business, "infant mortality" was used for brand new equipment that would break down a few hours before entering service.

Mainly Electrical Submersible downhole Pumps. For those non eruptive wells, you run a pump. Some of them, would fail a few hours or days after being started.

[p6x]

My company switched to RCM for many downhole tools.

Most of those tools are capable to determine when they require maintenance. 

Modern cars have some RCM built in too. My car tells me when I need to change the oil. It is always (a lot) later than the kind advice written by the dealership on that windshield sticker. lol...

[docc]

 

Frankly, those automotive, computerized feedback systems (RCMP) that say when to change the oil do not share my long term ownership goals.

 

[docc]

The Waddington Effect, though, is a very specific circumstance.

Some "thing" has been worked on (your motorcycle, your car, your truck, your boat, your plane, (your Bomber!) . . . and the result is compromised reliability for a time until the "glitches" and mishaps have been seen to. 

How many of us have gotten our (fill in the blank) back from the (fill in the blank: mechanic / dealer / factor / motor pool/ our-own-selves) and it fails from some nefarious effect of having been "messed with."  > cludged <  . . .  > farked <  . . . > porked <       

I would go so far as to suggest The Waddington Effect is the documented source study for the adage:

"If it ain't broke, don't fix it."