Spherical Oil & Gas Storage Tanks

History of Spherical Storage Tanks: the Horton Sphere

- David Grudzinski & Daniel Friedman

In the U.S. spherical tanks for the storage of liquids and gases were first described in detail by George Horton in the 1920s, the son of their inventor.

Spherical tanks proved ideal for storing materials under pressure, and as you'll read in this article, also for good seismic or other external force resistance.

Photo: a spherical oil storage tank discovered by Rhode Island home inspector David Grudzinski; the excavation contractor cleaned the tank and decided to keep it.

During and just after WWII spherical storage tanks were also made of concrete because of the shortage of steel in the U.S. (Wallace 1946) Horton's 1924 spherical tank patent described use of a sphere for storage of fuels including volatiles.

The Horton application was first filed in 1923!

Spherical storage tanks require the least surface area for a given volume of stored fuel, liquid or gas, so there is the least heat transfer between the tank and its surroundings - useful in some applications

Spherical storage tanks were historically used most-often to store gases or LPG

Spherical storage tanks are of particular use in areas where the tank may be exposed to seismic or other disturbances, and where a leak or explosion that could result would be catastrophic.

The first documented spherical tank was put up by CB&I in Fort Dodge, Iowa in 1892 for use to store water. (AOGH 2024 cited below). The spherical storage tank's inventor, Horace Ebenezer Horton, was a Chicago mechanical engineer who formed the Chicago Bridge & Iron Company, CB&I in 1889.

Horace Horton died in 1912 but his work and development of spherical storage tanks was continued by his son George Horton whose patents are cited and described below on this page.

Later, in 1934 Boardman, also described a spherical tank in 1934 and cited the need to address difficulties in thermal expansion and contraction of storage tanks.

CB&I is still a functioning business that we cite at the end of this article.

Cut-off copper tubing led to a buried Horton Sphere oil tank

David Grudzinski adds:

I was inspecting a home on the edge of a lake built in 1972. I saw evidence of copper fuel lines cut off penetrating the foundation of the home behind the oil boiler.

The homeowner bought the home 20 years ago and it had an exterior tank on a slab.

No one had ever suspected there was a buried oil tank on the property. I informed my client that this was evidence a buried tank had once been on the property.

No one had any idea if it was still present, or had been removed.

I searched around for some time with a ground probe, and eventually hit an object 18 inches below ground, but the size and shape was not consistent with a standard size and shape tank that would have been buried.

I decided it needed to be investigated so, with permission from the seller, I got to digging. I hit the tank surface 18 inches down, with 2 inch pipes consistent with the size for the fill and vent.

I informed the client and realtors the tank was there, and should be investigated to see if the tank contained oil. I received the attached photo from the realtor.

The tank is a 275 gallon Ball shaped tank. Ive never seen one before, and it resembled a wrecking ball. Pretty neat.

The tank was empty and had not leaked.

BTW: a fellow inspector told me his parent were in the HVAC wholesale biz in the 50s and these ball shaped tanks were remnants of WW11 bomb casings that they decided to use as oil tanks. I thought that was awesome. Some old buoys were also made from them.

- David Grudzinski, Rhode Island 2019/11/23

David Grudzinski, Advantage Home Inspections, ASHI cert # 249089, HUD cert# H-145, is a professional home inspector who contributes on various topics including structural matters.
David Grudzinski, Cranston RI serving both Rhode Island and Eastern Connecticut can be reached at 401-935-6547 fax- 401-490-0607 or by email to Davidgrudzinski@aol.com -
Mr. Grudzinski is a regular contributor to InspectAPedia.com

Spherical Storage Tank Research & Patents

• American Oil & Gas Historical Society, Horace Horton's Spheres, Petroleum Transportation [Website] "Chicago Bridge & Iron Company in 1923 began erecting giant, spherical pressure vessels"
  
  Excerpts
  
  Chicago Bridge & Iron Company (CB&I) officially named “Hortonspheres” — also called Horton spheres — after Horace Ebenezer Horton (1843-1912), the company founder and designer of water towers and rounded storage vessels.
  
  His son George would patent designs standing among the great innovations to come to the oil patch.
• Bradley, Benjamin Franklin. Oil-tank." U.S. Patent 1,189,048 [Patent web page] issued June 27, 1916.
  
  This is an example of an early oil storage tank that is cylindrical, not spherical.
• Boardman, Harry C. Support for spherical container U.S. Patent 2,417,053 [Patent web page] issued March 11, 1947.
• Boardman, Harry C. Spherical container U.S. Patent 1,953,949 [Patent web page] issued April 10, 1934.
  
  Excerpt: This invention relates to improvements in spherical containers and, more especially, to sheet metal spherical containers and supports therefor.
  
  The invention is especially applicable in connection with spherical containers adapted to contain fluids under pressure, for example, spheres holding compressed gas.
  
  It has been found that sheet metal spherical gas containers are subject to considerable expansion and contraction due to thermal and pressure variations.
  
  Owing to this expansion and contraction of the container, difficulty has been encountered in supporting the same
• Brinkman, Herbert C. Storage tank U.S. Patent 2,295,514, [Patent web page] issued September 8, 1942.
  
  Excerpt:
  
  In the spherical gas holders well known in the art, a metallic sphere is mounted upon a. foundation, usually consisting of a plurality of pedestals rising from the ground in a circle.
  
• Bryan, Blackburn. "Elevated storage tank." U.S. Patent 2,657,819, issued November 3, 1953.
  
• Daniels, Edwin G. "Method of making spherical containers." U.S. Patent 1,958,421, issued May 15, 1934.
  
• Dross, John C., Stephanus V. Stephanopoulos, and Dimitri L. Karlis. "Seismic response of spherical liquid storage tanks with a dissipative bracing system." In 5th GRACM International Congress on Computational Mechanics, Plimsoll, vol. 29, pp. 313-319. 2005.
• Fiori, Alessandra, Christoforo Martino, Rita Greece, Carlo Ago, Concetta Suspicious, and Ibo Vanni. Seismic performance of spherical liquid storage tanks: a case study [PDF] International Journal of Advanced Structural Engineering 10, no. 2 (2018): 121-130.
  
  Excerpts: Spherical storage tanks are widely used for various types of liquids, including hazardous contents, thus requiring suitable and careful design for seismic actions.
  
  On this topic, a significant case study is described in this paper, dealing with the dynamic analysis of a spherical storage tank containing butane. ...
  
  These tanks are usually named Horton sphere and are used for storage of compressed gases such as propane, liquefied petroleum gas or butane in a liquid–gas stage.
  
  The seismic analysis of spherical storage tanks requires to account for the fluid–structure interaction and for the soil–structure interaction.

• Horton, George T. Spherical Tank U.S. Patent 2,427,676 [Patent web page] issued September 23, 1947.
  
  Excerpt: This invention relates to elevated tanks for the storage of fluids, and relates particularly to a Spherical tank supported on circumferentially spaced columns.
  
  It has been found in the past that elevated tanks, and especially spherical tanks, are subjected to expansion and contraction caused by the heat of the sun, changes in temperature caused by the weather, variations in pressure, and the like.
  
  These expansions and contractions Sometimes tear the tank loose from its supporting legs or columns and thus many of these tanks re quire frequent and expensive repairs.
  
  They are especially bothersome with spherical tanks as it is difficult to attach supporting columns to the tank, this being usually done by welding the columns to the sides of the tank at points below the horizontal equator.
  
  As the columns are welded to the tank at an angle, any loosening of the welding by expansion or contraction immediately brings the weight of the tank to bear on the weakened portion and tends to tear the whole Column loose.
  
  A tank So Supported tends to rock back and forth and this fact increases the problem of providing adequate support for the spherical tank.
• Horton, George T., Elevated Tank U.S. Patent 2,358,805 [Patent PDF] issued 1944, filed by the Chicago Bridge and Iron Co., Horton's company, describes an elevated steel tank.

• Horton, George T. Elevated tank U.S. Patent 2,264,668 [Patent web page] issued December 2, 1941 and illustrated above.
  
  Excerpt: This invention relates to improvements in elevated tanks and more especially an elevated steel tank as is commonly employed for the storage of water and other fluids.
  
  Among the features of my invention is the provision of a substantially spherical tank supported on a substantially cylindrical riser pipe which in turn is supported by radial hollow tubular legs.
• Horton, George T., Tank Construction U.S. Patent 1,946,494 [Patent web page] issued February 13, 1934
  
  Excerpt: This invention relates to improvements in pressure tanks and method of making the same and, more especially, welded pressure tanks.

• Horton, George T. Tank. U.S. Patent 1,517,006 [Patent web page] issued November 25, 1924. Notice that unlike Horton's 1911 patent, this is a spherical tank, possibly the first actual Horton sphere tank that he patented.
  
  Excerpt: My improved tank is designed to withstand a considerable amount of pressure and still have a relatively large capacity.
  
  For example, the tank shown in this application is designed for capacity of substantially 433,000 gallons and has a diameter of substantially 48 feet.
  
  My improved storage tank is made spherical in form so that with the minimum amount of weight, a maximum amount of pressure may be held.
• Horton, George T. Water-tank U.S. Patent 1,184,347, issued May 23, 1916. [Like the 1911 patent, this is Not a Horton Sphere]

• Horton also patented water tank designs in Canada in 1915 - CA167400A, 1916 / 1917 - CA170434A, and 1917 - CA178822A
• Horton, George T., U.S. Patent Tank U.S. Patent 1,177,704 [Patent web page] Issued April 4, 1916, an improvement in water storage tanks.

• Horton, George T. Water-tank. U.S. Patent 1,008,645 [Patent web page] issued November 14, 1911. Illustrated above, you'll note that this is not a spherical tank.
  
  Excerpt:  The tank which is hereinafter described is designed to combine the advantageous features of the tank illustrated in said prior patent [1907] in that it may contain a maximum quantity of water with a minimum depth, while being constructed of economical proportions; it possesses great strength and rigidity .
• Horton, George T. Water-tank U.S. Patent 857,626 [Patent web page]issued June 25, 1907. Cylindrical, not spherical water storage tank.
• Jackson, James O. "Spherical type insulated container for liquefied gases." U.S. Patent 2,456,195, issued December 14, 1948.
  
• Jackson, James O. "Pressure storage tank." U.S. Patent 2,313,997, issued March 16, 1943.
  
• Jackson, James O., and Howell C. Cooper. "Low temperature storage tank." U.S. Patent 2,329,765, issued September 21, 1943.
  
• Kuehn, Paul M. "Tank." U.S. Patent 2,045,478, issued June 23, 1936.

• Marner, Charles L. Pressure storage tank." U.S. Patent 2,376,263 [Patent web page] issued May 15, 1945. Illustrated just above. Notice that the bottom of this tank is below ground.
  
  Excerpts [Edited for clarity by InspectApedia editor DF]: The invention relates to improvements in storage tanks and has reference more particularly to closed storage tanks tor storing volatile liquids under pressure, to thereby prevent the escape oil vapors from said liquids.
  
  An object of the invention is to provide a storage tank tor holding liquids under pressure.
  
  Another object of the invention is to provide a container for volatile liquids having an approximately spherical contour with adequately curved plates welded to each other to form a closed container.
  
  The container may be described as including two or more spherical, sections comprising the portion of the tank above ground level and which is provided with a dished bottom member having location below ground level.
  
  Each tank is a solid of a revolution about a vertical axis. One of the outstanding ter-cine [sic] for strengthening the tank against bursting or collapsing pressures induced by the vapors or air in the tank,
• Shanor, Edgar E. "Storage tank." U.S. Patent 1,835,815, issued December 8, 1931.
• Stanley, Pomykala Edmund. "Underground storage tank." U.S. Patent 2,382,171, issued August 14, 1945.

• Stuart III, Reece. Elevated storage tank U.S. Patent 3,363,795 [Patent web page] issued January 16, 1968. [Illustrated above]
• Wallace, Neff. "Storage tank and method of constructing same." U.S. Patent 2,413,243, issued December 24, 1946.
  
• Zerbe, F.K., SMITH CORP AO, 1938. Method of making a welded spherical vessel. U.S. Patent 2,118,388.
  
• Zhang, B. Y., H. H. Li, and W. Wang. "Numerical study of dynamic response and failure analysis of spherical storage tanks under external blast loading." Journal of Loss Prevention in the Process Industries 34 (2015): 209-217.
  
  Excerpt:
  The performance of energy infrastructures under extreme loading conditions, especially for blast and impact conditions, is of great importance despite the low probability for such events to occur.
  
  Due to catastrophic consequences of structural failure, it is crucial to improve the resistance of energy infrastructures against the impact of blasts.

Current Sources of Spherical Oil or Gas Storage Tanks

Note: any web search for "Horton Spheres" or "Spherical gas tank" or "Spherical oil tank" or "Spherical water tank" will return dozens of "hits".

At our last search in July 2025 we found companies in India dominating the search results, but CB&I, the originator of Horton sperhical tanks, remains in business in the U.S. in Texas.

• Bharat Tanks and Vessels, LLP B Type Bldg. Flat 21 / 22 B, Sr. No. 398 / A, Mayanagari, Phugewadi, Dapodi, Pune - 411012, Maharshtra, India Web: bharattanksandvessel.com/enquiry.php
• CB&I,1725 Hughes Landing Blvd, STE 600, The Woodlands, TX, United States, Texas (832) 513-4000 The company's address and direct contact information was hidden at their website (we found it on facebook) but they do provide this contact form: https://www.cbi.com/contact/
  
  Website excerpt: CB&I is the world’s leading designer and builder of storage facilities, tanks and terminals.
  
  CB&I Provides this CURRENT CATALOG of HORTONSPHERE PRESSURE VEHICLES [PDF] (local copy filed as Hortonsphere-Catalog-20251pdf)
• Spark Engineers, Bhosari, J 429, Bhosari M I D C Pune - 411026, Maharashtra, India Tel: +91 804 605 4883, Web: h parkengineers.org/horton-sphere.html