That Sunday Morning Call

[Overmod]

mudchicken

Someone not catching on that the railroad and the pipeline operation were owned by one of the same?

I don't think I did!  Time to review...

Thought UP didn't own SP until ~7 years after Duffy Street.  And that they'd sold Calnev to GATX Terminal about a year before...

[Erik_Mag]

Overmod

 

 

mudchicken

Someone not catching on that the railroad and the pipeline operation were owned by one of the same?

 

 

I don't think I did!  Time to review...

 

Thought UP didn't own SP until ~7 years after Duffy Street.  And that they'd sold Calnev to GATX Terminal about a year before...

 

Think MC was referring to yours truly, though I am a little confused if Calnev was an SP or UP owned company. My impression was that SP's ppipelines were in general laid of SP ROW, one exception that I'm aware of was the joint AT&SF/SP pipeline from LA to San Diego.

Having had experience with the working of large companies, it certainly wouldn't surprise me that the left hand didn't know what the right hand was doing.

[Overmod]

Erik_Mag

Think MC was referring to yours truly, though I am a little confused if Calnev was an SP or UP owned company.

References I have are to UP; if I'm not mistaken the refineries of product were UP 'first'.

ISTR a discussion in one of the "Government" discussions that Calnev came down the mountain partly in its own ROW, only followed the railroad ROW a comparatively little distance, and ran across the SP in the Duffy Street area.  I will keep looking as I have time.

See for example the sketch-map in figure 3.4.1 here:

https://www.fema.gov/media-library-data/20130726-1514-20490-8772/fema_225_pt_2.pdf

Why this map does not show railroads explicitly I do not know, but it would not be tough to overlay.

[Erik_Mag]

Overmod

I was thinking that high-octane had a higher vapor pressure ... but on reflection, I think I am indeed reporting a comparatively unimportant but highly prejudicial innuendo about the 'high-octane' detail.

The innuendo that has been an all too common in news reports about gasoline fires... OTOH, one relatively inexpensive way of improving octane rating is increasing the butane content, but this works best for winter fuels.

Yes, I am aware of the primary purposes of higher-octane fuel

I had no doubt about that - you've demonstrated that you have a very good understanding of combustion.

[Erik_Mag]

Overmod

 

Erik_Mag

Think MC was referring to yours truly, though I am a little confused if Calnev was an SP or UP owned company.

 

References I have are to UP; if I'm not mistaken the refineries of product were UP 'first'.

 

I suspected UP as it had the ROW to Las Vegas. FWIW, the San Diego pipeline is a fair distance away from the Surf Line through most of San Diego county south of Camp Pendleton.

Both the pipeline construction and accident happened before UP bought the SP. Definitely different ownership of the railroad and pipeline at that time (you, MC and I were either in Jr High or High school when the pipeline was originally constructed. BTW,the "Kinder" in Kinder Morgan (current Calnev owner) is Rich Kinder who bailed out of Enron a couple of years before it imploded.

I did a couple of quick looks at the NTSB report, one interesting point was that the yield strength and ultimate tensile strength of the pipe was higher than what the specifications called for (usually a good thing). Spec's were 52kpsi for yield strength and 66kpsi for UTS, testing showed yield strength at 66kpsi and UTS at 74.3kpsi. The reduction in spread between yield strength and UTS suggests a more brittle steel...

My perhaps imperfect understanding of rules for placing pipelines under RR tracks is that the pipe needs to be placed in a casing, with such casing to prevent this type of accident. This is something where MC would be much more authoritive source.

[ericsp]

NTSB's Finding 26: "Calnev's pipeline met the industry-recommended safety requirements in effect when it was constructed; no State or Federal regulations were in effect at that time."

The report also says that it was pressurized to over 1,600 psig.

https://www.ntsb.gov/investigations/AccidentReports/Reports/RAR9002.pdf

[Erik_Mag]

I remember seeing that in the report, industry standards are adequate for an undisturbed pipeline. In other words, the standards assumed the major stress on the pipe would be the hoop stress from the interior pressure.

The standards called for steel with a yield strength 79% of the ultimate tensile strength, while the pipe in question had a yield strength 89% of the ultimate tensile strength. IIRC, the AAR prohibited use of materials with yield strength in excess of 80% of the UTS in the primary structure (e.g. center sill, bolsters) of a railroad car. This ruled out all aluminum cars. The point of the ARR rule was that a ductile sill would deform but otherwise remain intact under a high impact, where the brittle material would fail catastrophically.

(A perfect piece of glass has a significantly higher tensile strength than steel. Just rubbing a finger over such a piece of glass can reduce the tensile strength by a factor of 10 due to the microcracks.)

In the case of the Calnev pipeline, the forces imposed by the derailment and heavy equipment in the cleanup would have caused the pipe to further work harden and reduce the margin between yielding and brittle fracture. My guess is that the gouges from the backhoes caused a stress concentration in the pipe which led to a developing crack that got worse with each train passing over it due to the brittle steel. A ductile steel would have yielded and thus minimized the stress concentration.

FWIW, a similar issue is present with pressure vessels for nuclear reactors, where neutrons escaping the core cause an increase in the brittle transition temperature. Th e pressure vessels have coupons that are removed periodically and tested to ensure that the metal stays within spec.