# What does the colonial pipeline actually carry....fuel, yes..but how? **URL:** \ **Category:** Factual Questions\ **Created:** [May 11, 2021, 11:27pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873 "2021-05-11T23:27:42Z")\ **Posts on this page:** 16\ **Page:** 2
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [May 13, 2021, 2:04am UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/22 "2021-05-13T02:04:02Z")
> [@md-2000](#): > > As was the young punks who would drive up to some farm in the middle of the night and fill up from the farmer’s supply of dyed gasoline. In the last couple of days I saw a youtube video where a farmer was talking about an old trick of having a prominent “gas tank” near the road into which you would put all of your oil slops (used motor oil, diesel with water in it, etc) knowing full well that would be the tank that thieves would steal from. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [May 13, 2021, 2:44am UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/23 "2021-05-13T02:44:32Z")
Excellent plan! For a while at least. I would think the thieves would get wise to that before too long. Then what happens? ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [May 17, 2021, 9:01pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/24 "2021-05-17T21:01:13Z")
You’re right, but it looks like maybe they just reprocess the “trans-mix”. [The multi-product pipeline scheduling system - ScienceDirect](https://www.sciencedirect.com/science/article/pii/S0898122108000904#:~:text=Batches%20of%20different%20refined%20products,1). ---
**Author:** ![Omar\_Little](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/omar_little/32/269_2.png) [@Omar\_Little](https://boards.straightdope.com/u/Omar_Little)\ **Post date:** [May 19, 2021, 5:31pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/25 "2021-05-19T17:31:10Z")
The mixture of different grades of refined products transported in a pipeline is called “transmix”. Transmix is separated out and stored in a different tank for re-processing. Transmix will have different values depending on what two types of products have been mixed. In many cases the octane value is used to determine the value and level of re-processing is needed. You normally don’t ship crude oil and refined products into the same pipeline. There are different pipelines for each, as the fluidity, specific gravity and transmix problems would not work. The majority of shippers on a refined products pipeline, like Colonial, are wholesalers of such products. They are typically not the retailers that operate the branded gas stations in your local market. The retailers buy the different grades of gasoline from the distribution points along the pipeline. So yes, the Shell station and the Exxon station across the street, are all selling the same gasoline from the same wholesale refinery that loaded the gas in the pipeline along the Gulf coast. They will put in their own additives for their branding purposes. But for all practical purposes it’s the same gas. ---
**Author:** ![filmstar-en](https://avatars.discourse-cdn.com/v4/letter/f/50afbb/32.png) [@filmstar-en](https://boards.straightdope.com/u/filmstar-en)\ **Post date:** [May 19, 2021, 6:35pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/26 "2021-05-19T18:35:22Z")
This account on how pipelines work in the US, says that Colonial publishes specifications for 100 different grades of gasoline their pipelines can carry. > **[451\_2\_31375.pdf](https://www.iatp.org/sites/default/files/451_2_31375.pdf)** ---
**Author:** ![KMS94](https://avatars.discourse-cdn.com/v4/letter/k/ad7895/32.png) [@KMS94](https://boards.straightdope.com/u/KMS94)\ **Post date:** [May 19, 2021, 10:32pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/27 "2021-05-19T22:32:20Z")
> [@md-2000](#): > > I assume though, adding the dye is something done at the last possible stage of processing/wholesale? I used to work for a fuel delivery company, and would drive a tanker to the terminal to fill up. I would connect the piping to the truck, and “place my order” on a simple touch screen. All the Diesel came out of the same hose, and it was all ultra-low sulfur blend. There was an inspection window in the terminal’s pipe, at eye level, and you could watch the clear Diesel rushing through the 6" pipe at great speed. If you had ordered dyed, every 50 or 100 gallons or so, you’d hear a whooshing noise and could see the clear Diesel turn dark, dark red when it got a shot of the dye added from the injector right above the window. So yes, it’s at the very last moment of wholesale, as it’s going in to the delivery truck. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 19, 2021, 10:51pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/28 "2021-05-19T22:51:35Z")
> [@txtumbleweed](#): > > At the receiving end, the pump station knows how much of each fuel is coming and as the flow of fuels get to the terminal, the system is counting not just the gallons incoming, but also sensing the density. How do you measure the density of a moving fluid? If you have a tethered float, it will be moved by the flow. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 19, 2021, 10:53pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/29 "2021-05-19T22:53:06Z")
> [@Senegoid](#): > > Excellent plan! For a while at least. I would think the thieves would get wise to that before too long. Then what happens? Then they set your gas tank trap on fire. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [May 20, 2021, 12:49am UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/30 "2021-05-20T00:49:41Z")
> [@filmstar-en](#): > > This account on how pipelines work in the US, Today I learn that pipeline operators are “common carriers”. Previously, the only time I had ever seen the term was in Airline / Courier documentation asserting “we are not a Common Carrier”. I’d often wondered if such a thing even existed. ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [May 20, 2021, 7:18am UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/31 "2021-05-20T07:18:06Z")
Common carriers have a high degree of liability for loss & damage to goods, at common law. Which is why carriers tend to seek to make it clear they are not common carriers. Ironically, IME at least in Australia carriers that would otherwise fit the definition of “common carrier” tend to be quasi governmental (eg railways) and tend to have specific statutes exempting them from any sort of liability whatsoever. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [May 20, 2021, 11:11am UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/32 "2021-05-20T11:11:33Z")
> [@carnivorousplant](#): > > How do you measure the density of a moving fluid? If you have a tethered float, it will be moved by the flow. You can use a coriolis meter: > **[Mass flow meter | Density and volume measurements](https://en.wikipedia.org/wiki/Mass_flow_meter#Density_and_volume_measurements)** > > The mass flow of a U-shaped Coriolis flow meter is given as: > > > > > > Q > > m > > > = > > > > > K > > u > > > − > > I > > u > > > > ω > > 2 > > ... ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 20, 2021, 5:39pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/33 "2021-05-20T17:39:13Z")
Thanks, Machine\_Elf. ---
**Author:** ![txtumbleweed](https://avatars.discourse-cdn.com/v4/letter/t/278dde/32.png) [@txtumbleweed](https://boards.straightdope.com/u/txtumbleweed)\ **Post date:** [May 20, 2021, 6:11pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/34 "2021-05-20T18:11:13Z")
This is in the 80’s in training so we did it all manually. There was a tap on the incoming line as it got to the spider (the distribution rack where you would shunt fuel to/from any of the tanks in the tank farm). You would pull about a cup of fuel or so into a beaker and drop the hydrometer in and measure the density manually. From there it was look up the temperatures and adjust for those, then do it again until the density curve was right for the next batch of fuel coming through the line. Like everything military, there was a specific procedure for when and how often to draw samples during the flow. Not surprised to see, as noted above, that there is a flow meter to take the readings for you automatically. Honestly, I figured by this time they likely had some sort of laser type rig to continuously measure temp and density so the computer could through the valves automatically. ---
**Author:** ![Precambrianmollusc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/precambrianmollusc/32/63_2.png) [@Precambrianmollusc](https://boards.straightdope.com/u/Precambrianmollusc)\ **Post date:** [May 20, 2021, 11:05pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/35 "2021-05-20T23:05:03Z")
For what’s it’s worth the Colonial pipeline system consists of two pipeline , one is generally dedicated to distillates ( diesel, heating oil jet fuel) the other is for gasoline products so they are not mixing very dissimilar stuff in a single pipeline. ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [May 24, 2021, 11:44pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/36 "2021-05-24T23:44:45Z")
> [@Machine\_Elf](#): > > You can use a coriolis meter: I _really_ wanted to answer this question—I used to design flowmeters, including Coriolis meters. But I missed my chance and you nailed it. 🙂 You can theoretically measure density with an ultrasonic flow meter and a few other ways, but Coriolis meters measure density directly, and that’s how it’s typically done in the petrochemical industry. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [May 25, 2021, 8:38pm UTC](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873/37 "2021-05-25T20:38:38Z")
> [@txtumbleweed](#): > > This is in the 80’s in training so we did it all manually. I actually had a coriolis meter in the 80’s. [Previous page](https://boards.straightdope.com/t/what-does-the-colonial-pipeline-actually-carry-fuel-yes-but-how/941873.md?page=1)