delivered the opinion of the Court.
This appeal involves the right of the complainant, Roane-Anderson Company, a Tennessee corporation, to recover certain privilege taxes which it paid under protest. The Commissioner of Finance and Taxation assessed these taxes against the complainant as a result of its activities pursuant to its contract with the Atomic Energy Commission.
In the original bill seeking a recovery of these taxes it is charged that complainant was acting as the agent of the United States Government; that the contract, under which it operated, designated the complainant as *377such agent, and all of its activities have been as the authorized agent of the Federal Government, and for this reason the assessment was in violation of the Supremacy Clauses of the Federal Constitution, namely, Article I, sec. 8, Clause 18, and Article VI, Clause 2, of the instrument.
The United States Government filed an intervening petition, making the same contention. It was later stricken by the Chancellor on motion of the defendant. An exception was taken.
The defendant answered the bill and denied that the complainant was acting as agent of the United States Government, and insisted that it was an independent contractor and was subject to the State tax statutes, which rendered it liable for sales and use taxes, and gross receipts taxes.
These cases were brought by the complainant to collect the taxes paid, and “to test the liability of Roane-Anderson Company and as far as possible the liability of certain Government contractors on the Oak Ridge Area, for certain State privilege taxes for the period 1944 through 1946. ’ ’ To this end the bill seeks a declaratory judgment.
The Chancellor held, upon a review of the record, that the complainant was not an agent of the Government but was acting as an independent contractor; that it was exercising all of the privileges claimed by the State of Tennessee, and that the taxes paid under protest were legally exacted.
He further held and decreed that under the circumstances it would be inequitable and unjust for the complainant to be onerated with the burden of paying inter*378est and penalties and that the Commissioner should pay ■ to the complainant the amount of penalties and interest which had been paid under protest.
Roane-Anderson appealed from the aforesaid holding of the Chancellor, and the Commissioner also appealed. Numerous errors have been assigned by Roane-Ander-son. The principal error relates to the decree which finds and holds that the Roane-Anderson Company was acting as an independent contractor with the United States of America. A decision of this sharply disputed issue will be determinative of several other assignments, which will be later considered in this opinion.
Upon the question of agency as against the status of independent contractor we are challenged by the following contention:
“Second: The learned Chancellor erred in holding that all of the elements which were before him in this suit insofar as is necessary for a determination of the question of agency as against the status of independent contractor were before the Court in the Roane-Anderson Company Sales Tax Cases (Roane-Anderson Co. v. Carson, 192 Tenn. 150, 239 S.W.2d 27), and that the determination as made in those cases is controlling in the present suits.”
"We will refer hereafter to Roane-Anderson Co. v. Carson as the Carson Sales Tax case. The majority opinion by Mr. Justice Burnett gives a complete history of the vast development of the Oak Ridge Area by the Federal Government. It was sponsored by the Government for the sole purpose of making nuclear weapons as “ ‘potentially destructive beyond the wildest nightmares of the imagination,- * * *. This weapon has been created not by the devilish inspiration of some warped genius but by *379the arduous labor of thousands of normal men and women working for the safety of their country.’ Smyth Report, Page 163, released in August, 1945.” [192 Tenn. 150, 239 S.W.2d 29.]
It is pointed out in that opinion, 192 Tenn. at page 158, 239 S.W.2d at page 30, “The land and all facilities in the plant at Oak Bidge are wholly owned by the United States government.” We might say in passing that this continues to be true now as it was then. It was strictly a G-overnment operation.
Begarding the nature of the operation and the risk of invested capital, it is said:
“The contractors are not required to risk their own money in the operation of Commission facilities. This provision of the contract obviously came about by reason of the enormity of the project, the newness of what was being done and of the uncertainty of the result. It is said that ‘regardless of what happened the government would pay the bill’ and it was on this basis that the contracts were originally made with the various companies in the production of Atomic energy. All the contracts have a ‘hold-harmless’ provision and the expenses and procurements are on a reimbursable basis.”
It was necessarily a secret operation in order that the enemy not be apprised of the development of a weapon so destructive that a great city could be wiped out by a single atomic bomb. This secrecy was fully justified.
The repeated declaration in the contract that Boane-Anderson is the agent of the United States Government, and that this status was accepted and acknowledged by Boane-Anderson was conclusive upon the par*380ties to this contract. But not so as to others and especially the State of Tennessee’s right to levy and collect taxes from individuals and agencies who were exercising taxable privileges which were admittedly authorized by law.
In considering the relationship of the parties in the case now before us we must examine the contract in its entirety, the nature and use of the physical properties, as well as its ownership, and the activities of any and all persons engaged in operating the Oak Ridge project, and thus determine the intention of the parties.
The said contract was on the usual cost-plus basis of remuneration for services rendered. The contractual duties to be performed by Roane-Anderson were so varied and multitudinous that they could not be foreseen and specified in any written instrument. These activities were performed subject to Government approval. It conclusively appears that every duty performed by Roane-Anderson, its agents and servants, was in the use of Government property and Government facilities, all of which was to accomplish one single purpose, namely the production of an atomic bomb for use by the Armed Forces of the United States of America. But this is not sufficient in and of itself to justify us in holding that the collection of charges for the use of Government property, such as rental to employees of houses, to concessionaires, and other like operations, is exempt from State taxation, provided the tax so levied is not laid upon the property itself and does not interfere with or embarrass the Government in the unfettered use of its property.
The foregoing was in substance the basis of our holding in the Carson Sales Tax case, that Roane-Anderson was an independent contractor, but was exempt from the *381tax by reason, of Section 9(b) of the Act of Congress creating the Atomic Energy Commission. The Conrt rested its opinion largely npon James v. Dravo Contracting Co., 302 U.S. 134, 58 S.Ct. 208, 82 L.Ed. 155, 114 A.L.R. 318, and State of Alabama v. King & Boozer, 314 U.S. 1, 62 S.Ct. 43, 86 L.Ed. 3, 140 A.L.R. 615. Bnt for the exemption provided for in the Act of Congress, supra, the State tax as levied was lawful and did not encroach npon Federal authority.
Contention is made by counsel for Roane-Anderson that our decision in the Carson Sales Tax case is not res judicata as to the issue involved in the case at bar. It is insisted that the facts here are vastly different. It is true that in the instant case there appears testimony as to the exact use of Government property by Roane-An-derson and not brought out in the former case. Moreover the Court rested its decision on the authority of State of Alabama v. King & Boozer, supra, that the cost of material purchased by Roane-Anderson, and other contractors, to be used in furtherance of the Oak Ridge project was subject to our Sales Tax Statute. In the instant case the tax exacted is upon Government owned property and revenue derived from such property.
The doctrine of Collateral Estoppel cannot be applied in tax cases unless the identical taxes are involved in the second or later suit. State v. Bank of Commerce, 95 Tenn. 221, 31 S.W. 993; Union & Planter’s Bank v. City of Memphis, 101 Tenn. 154, 46 SW. 557. See also, Willis v. Willis, 48 Wyo. 403, 49 P.2d 670.
The facts developed in the case at bar give rise to the contention by Roane-Anderson that the tax levied and sought to be exacted constitutes an interference with Federal authority in the Oak Ridge Area, and is in effect *382a tax -upon Government property. This question is presented for the first time, both in the trial court and on this appeal. The contention is made that the tax here exacted is in violation of the Supremacy Clauses of the Federal Constitution. The counsel for Roane-Anderson, in support of this insistence, rely strongly upon Mayo v. United States, 1943, 319 U.S. 441, 63 S.Ct. 1137, 87 L.Ed. 1504, and Kern-Limerick, Inc. v. Scurlock, 1954, 347 U.S. 110, 74 S.Ct. 403, 98 L.Ed. 546. Whether or not these cases are controlling in the case at bar depends in a large measure upon the activity of Roane-Anderson in the control, use and management of Government property.
It is insisted (1) that Roane-Anderson was not engaged in operating a Transportation Company, i. e., the operation of Government owned buses, and hence not subject to a tax on gross receipts; (2) that it is not engaged in the business of Furnishing and Distributing Water and/or Electric Current; (3) that the Motor Vehicle Act does not require Roane-Anderson to pay the Registration Fees on the truck; if it does, it is in violation of the Federal Constitution.
Other like contentions are made by Roane-Anderson with reference to the control and use of other properties of the Government from which revenue was collected.
It is not disputed that Roane-Anderson and its employees are operating a number of buses “on the Area” and “off the Area” for the benefit of numerous employees at Oak Ridge, many of whom live inside the Area and some outside of the Area. These vehicles are the property of the Federal Government.
Roane-Anderson has full control of a system of waterworks in which water is obtained from the Clinch River and supplied to every agency connected with the Oak *383Ridge project. Most, if not all, of these agencies pay for their service to Roane-Anderson. The system is owned by the Government.
Roane-Anderson is in authority over the use and distribution of electric current throughout the Oak Ridge Area. But it is wholly Government property. Fees for this service are paid to the Roane-Anderson Company.
We deem it unnecessary to refer to other similar activities. The question posed for decision, do these assessments so levied and collected, amount to a subjection of Federal owned property to a State tax, such as, a license to operate a bus, truck, etc., a gross receipts tax, a tax upon seating capacity of buses, the same being so much upon every seat?
Now it will hardly be denied that the functions of the Federal Government would be greatly impaired, if not completely paralyzed, if these operations should cease. It is not conceivable that the Commissioner of Finance and Taxation, or any other State agency, could levy a distress warrant upon any Government property for the failure of Roane-Anderson to pay these taxes.
Turning now to the cases relied on by Roane-Anderson, in Mayo v. United States, supra, the State of Florida undertook to impose an inspection fee upon a shipment of fertilizer into the State, which was the property of the Federal Government. It was held (opinion by Mr. Justice Reed):
“These inspection fees are laid directly upon the United States. They are money exactions the payment of which, if they are enforceable, would be required before executing a function of government. Such a requirement is prohibited by the supremacy *384clause. We are not dealing as in Graves v. People of State of New York, supra [306 U.S. 466, 59 S.Ct. 595, 83 L.Ed. 927], with a tax upon the salary of an employee, or as in State of Alabama v. King & Boozer, 314 U.S. 1, 62 S.Ct. 43, 86 L.Ed. 3, 140 A.L.R. 615, with a tax upon the purchases of a supplier, or as in Penn Dairies v. Milk Control Commission, 318 U.S. 261, 63 S.Ct. 617, 87 L.Ed. [748], decided March 1, 1943, with price control exercised over a contractor with the United States. In these cases the exactions directly affected persons who were acting for themselves and not for the United States.” [319 U.S. 441, 63 S.Ct. 1140.]
In Kern-Limerick, Inc., v. Scurlock, supra, the question decided was the legality of the Arkansas gross receipts tax of 1941 where it was exacted of private contractors engaged in a joint venture, and who had purchased two diesel tractors costing $17,146 for use in constructing an ammunition depot for the United States. The Court ruled that the “transaction would concededly make Kern-Limerick liable for the tax if the real purchaser were not the United States.” [347 U.S. 110, 74 S.Ct. 405].
In this case the United States intervened, as in the case at bar, because under its contract it agreed to reimburse Kern-Limerick. The Court distinguished James v. Dravo Contracting Co. and State of Alabama v. King & Boozer, supra, from the case then under consideration. In pointing a distinction between the case and State of Alabama v. King & Boozer, the Court has this to say:
“A phase of the question reserved in the Dravo case came up in State of Alabama v. King & Boozer, 314 U.S. 1, 62 S.Ct. 43, 86 L.Ed. 3 [140 A.L.R. 615]. We declared that federal sovereignty ‘does not spell *385immunity from paying tlie added costs, attributable to the taxation of those who furnish supplies to the Government and who have been granted no tax immunity.’ * * #
“The doctrine of sovereign immunity is so embedded in constitutional history and practice that this Court cannot subject the Government or its official agencies to state taxation without a clear congressional mandate. No instance of such submission is shown.” (Emphasis supplied.)
Now for further consideration of contentions made by the defendants, a declaratory judgment having been sought in these cases as to the complainant’s liability for base taxes during the period of January 1, 1944, through December, 1946, we hold that the receipts of revenue from Government owned property, such as buses (“seat” tax), trucks, and automobiles, owned and used for the transportation of employees on the Oak Ridge project, as well as collections from other agencies, cannot be made the basis for assessing and collecting gross receipts taxes by the Commissioner of Finance and Taxation.
The mere fact that the Congress repealed Section 9(b) of the Act creating the Atomic Energy Commission does not affect the title, ownership, and operation of Government property by the Roane-Anderson Company, and this is true whether Roane-Anderson was acting as an agent under its contract with the Atomic Energy Commission or as an independent contractor.
It cannot be denied that Roane-Anderson was engaged in the performance of a public duty mandatorily required by the Act of Congress. The fact that Roane-Anderson was a private corporation, and acting pursuant *386to a valid contract with the authority, set up by Congress, does not give it the aspect of a private business. It was engaged in no commercial activity for profit. Its sole taxable income was the fee which the Government had contracted to pay it for its services. The property which had been purchased by Boane-Anderson, Carbide & Carbon Chemicals Corporation and other contractors (see Carson Sales Tax case) for completing the Oak Bidge project became vested in the United States Government. The revenue derived therefrom could not be made the base for collecting these taxes in violation of the Supremacy Clauses of the United States Constitution as held in the Federal decisions above recited. The cases of Youngstown Sheet & Tube Co. v. Sawyer, 343 U. S. 579, 72 S.Ct. 863, 96 L.Ed. 1153, and Powell v. United States Cartridge Co., 339 U.S. 497, 70 S.Ct. 755, 94 L.Ed. 1017, relied on by the defendant have no application to the foregoing determinative issue. The Youngstown case involved a seizure of private property by the Government. Nor is there any question here involving conscription of industry under the control of the military.
It would unduly prolong this opinion to attempt to discuss other eases cited by defendant’s counsel and distinguish them. Many of them relate to collateral issues.
We cannot escape the conclusion that revenue derived from the right to occupy and use Government property is as much Government owned as the property itself. If this be true, it is clearly not subject to the tax sought to be exacted in this present litigation. For this Court to entertain a different view would run counter to McCulloch v. State of Maryland, 4 Wheat. 316 4 L.Ed. 579.
*387We are therefore constrained to sustain complainant’s assignments of error (1) that the Chancellor erred in dismissing’ the complainant’s hills. We think they should have been sustained and a decree to this effect will be entered, allowing a recovery of the sums of money paid under protest with interest thereon as provided by law. (2) It was error to dismiss the intervening petition of the United States Government. A decree in this Court will be entered sustaining the bill.
Other assignments of error are pretermitted because they are foreclosed, and are fully disposed of in our discussion and disposition of the principal assignment.
We deem it unnecessary to make specific reference to the defendant’s assignments of error and discuss them in detail. They have been considered and dealt with in connection with the complainant’s assignments. Suffice it to say if Roane-Anderson Company is entitled to recover the sums of money paid under protest, it would include not only taxes illegally assessed, but interest and penalties as well.
Inasmuch as Roane-Anderson Company is, in our opinion, entitled to a decree in its favor, for reasons stated in this opinion, it is immaterial that the Federal Government was not allowed to intervene; nor is it material that the Chancellor declined to sustain the defendant’s plea of res judicata, for the stated reason that the doctrine of Collateral Estoppel has no application to the case at bar.
The questions raised in the two cases are to all intents and purposes the same. Our disposition of the assignments will apply to both cases, and the foregoing opinion will be considered as authority in each case.
*388Tomlinson and Buiínett'. Justices, concur.