This weekend, I flew back up to Long Island for a family wedding. The view from the air gave me an interesting perspecitive as a modeler. First thing I noticed: I flew over several large tank farms. I noticed that some tanks had roofs flush with the top of the tank, others had their roofs depressed into the tank. Another thing I saw was several rock quarries had large pond of water that were a almost jade green color. I'm not sure I;ve ever seen these details modeled however.
Modeling the Pennsylvania Railroad in N Scale.
www.prr-nscale.blogspot.com
GP-9_Man11786 I noticed that some tanks had roofs flush with the top of the tank, others had their roofs depressed into the tank.
I noticed that some tanks had roofs flush with the top of the tank, others had their roofs depressed into the tank.
You might have seen something like this:
Ed
The tanks you were looking at have roofs that move up and down. The weight of the roof provides the pressure to move the product out of the tank. These are usually used for natural gas.
SouthPenn The tanks you were looking at have roofs that move up and down. The weight of the roof provides the pressure to move the product out of the tank. These are usually used for natural gas.
Those would be "gas holders":
https://en.wikipedia.org/wiki/Gas_holder
They are getting to be quite rare in the US. When you see them, they will likely be standing alone and in an urban area.
Here's more on "external floating roof tanks":
https://en.wikipedia.org/wiki/External_floating_roof_tank
These tend to be in groups. Note the continuous reference to liquids in the article, as opposed to gas.
7j43kThose would be "gas holders":
The plant I worked at had ten of them!
Fascinating pieces of equipment.
Regards, Ed
Wow.
I've seen an assortment of singles from back in the day. That many is impressive. I remember one prominently featured near the waterfront of Oakland, CA. It was always there, doing its thing. Now it's long gone. I don't recall another for miles around, so I'm assuming it was "the one" for Oakland and environs.
I think I've read that they don't need/use them on natural gas distribution systems anymore because the supply is so well regulated.
I'm curious. Why were there 10? What were you guys doing?
Oil tanks also have floating tops. We have the largest oil refinery in Canada in out city, and many of their tanks are like this.
Bob Boudreau
CANADA
Visit my model railroad photography website: http://sites.google.com/site/railphotog/
Hello all,
Yes, aerial views can be an amazing perspective. That’s why Google Earth can be so helpful to modelers.
Where I grew up there was a floating tank that supplied water, not gas or oil.
During the drought of the 1970's the level of the tank was at it's lowest point; fully compressed or collapsed.
As far as the color of the water you observed, here in the mining country of Colorado, many times that emerald green color comes from copper sulfate; a by-product of the mining industry.
You can see this in the abandoned settling ponds and some streams.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
7j43kI'm curious. Why were there 10? What were you guys doing?
Making those old things we used to call light bulbs. We had two liquid air columns and extracted all sorts of gases all the way down to the Noble gases, neon, helium, krypton and xenon.
The larger holders, 250,000 ft3 were nitrogen, hydrogen and oxygen, the smaller ones (6,000 ft3) were argon, fuel gas, forming gas and...something else? Well, that was thirty years ago. One holder was a spare that could be pressed into service during the repair of others.
Here's a crop showing the holders:
These had a water seal between the stages. A fun filled day was climbing up in that rigging on a windy, ten degree night with a steam line to thaw out the guide rollers or water piping!
We purified, mixed and compressed the gases to ship to lamp plants all over the U.S. and Canada.
Railphotog Oil tanks also have floating tops. We have the largest oil refinery in Canada in out city, and many of their tanks are like this.
Floating roof tanks are used for more voliatie fluids like gasoline. It reduces the evaporation and keeps an explosive vapor mixture from forming in the tank as the fluid level goes up and down. The vapor could be detonated by static electricity discharge.
Fixed roof tanks have a breather vent in the top to allow air to enter or escape when the level changes, otherwise the tank could rupture from over pressure on increasing level or collapse when the level drops making a partial vacuum.
George In Midcoast Maine, 'bout halfway up the Rockland branch
A website I have visited from time to time is called Historic Aerials - I was able to find aerial photos over a wide time frame of the area I model. Very helpful, especially the older ones.
http://www.historicaerials.com/
Dave Nelson