This action for declaratory relief was commenced by the respondent, Amco Insurance Company, which sought a judgment declaring that it was not obligated to defend a civil action pending against the appellant, Paul Chesley, or to pay any resulting judgment. After both parties had moved for summary judgment, the district court granted summary judgment in favor of the respondent. The appellant appeals from this judgment and requests that it be reversed, and that judgment be entered in his favor or that the case be remanded for a trial. The other defendants in this action are the plaintiffs in the personal injury action pending against the appellant, and they have not joined in this appeal.
The appellant seeks to hold the respondent liable to defend an action which arose *162as a result of the detachment of a portable welder which was being towed behind a pickup truck owned by the appellant and insured by the respondent; after coming loose, the welder was struck by another vehicle, and serious injuries resulted to its occupants. At the time of the accident, the appellant’s principal occupation was well drilling. The portable welder was owned by James Eaton, who hired the appellant to drill a well near Hagerman, Idaho. On the day of the accident, the appellant borrowed the portable welder from his employer, and while driving to the well site, it came loose and subsequently was struck by the Fairchild automobile.
The insurance policy issued to the appellant provides coverage for liability arising out of the “use of the automobile”; it also contains the following definitions:
“XV * * *
(a) Automobile. * * * [T]he word ‘automobile’ means:
* * * * * *
(2) Trailer — * * * a trailer not described in this policy, if designed for use with a private passenger automobile, if not being used for business purposes with another type automobile * * *.
>}C * * * * *
(b) Private Passenger Automobile. The term ‘private passenger automobile’ means a four-wheel private passenger, station wagon or jeep type automobile.” The question decisive of this appeal is
whether the portable welder was a “trailer” as defined in the insurance policy; for if it was not such a trailer, then there is no apparent basis for concluding that the policy covered liability arising out of the use of an “automobile,” as defined in the policy. It is the conclusion of this Court that the portable welder was not a trailer, within the meaning of the policy, because it was not “designed for use with a private passenger automobile.”
In Lewellyn v. State Farm Mutual Automobile Insurance Co., 222 Tenn. 542, 438 S.W.2d 741 (1969), the insured was pulling a borrowed “mobile welding rig,” which came loose, causing damage to another automobile and a passenger therein. The Supreme Court of Tennessee held that the welding rig was a trailer designed for use with other than a private passenger automobile. Similarly, it has been held that a “mobile pump” was a trailer not designed for use with a private passenger automobile. Liberty Mut. Ins. Co. v. Allied Mut. Ins. Co., 442 F.2d 1151 (10th Cir. 1971). In both of the cited cases, the insurance policy provisions were substantially the same as those involved in the case at bar.
The appellant notes that the portable welder could have been pulled by any type of vehicle — including a private passenger automobile — equipped with a trailer hitch containing a hole for fastening the tongue of the trailer to the motor vehicle by means of a bolt or a rod. However, the phrase “designed for use with a private passenger automobile” may not be deemed synonymous with “capable of being towed by a private passenger automobile.” As the court stated in Liberty Mutual Insurance Co. v. Allied Mutual Insurance Co., supra:
“We do not at all say that the district court erred in its painstaking effort to define ‘trailer’. Its error, as we see it, lay in not attaching more significance to the limitation trailing ‘trailer’, i. e., ‘designed for use with a private passenger automobile.’ If these words were given any significance, they were deemed synonymous with ‘capable of being drawn and towed’ by a private passenger automobile. This interpretation renders them meaningless for obviously something which cannot be drawn or towed will never become involved in an accident, at least one between moving vehicles. By the same token, if a trailer is equipment which can be ‘trailed’, then construing the limiting language as the court did, if it construed it at all, would have us read the policy as covering ‘equipment which can be trailed if capable of being drawn or towed by a car.’ So read, the clause would be a classic of redundancy. On the other hand, ‘de*163signed for use with’ seems to us to connote an object planned with a particular use in mind and so manufactured as to serve that use with reasonable efficiency and safety.
******
We conclude that the mobile pump was not a ‘trailer designed for use with a private passenger car’. Allied quite reasonably declined to accept responsibility for everything its policyholders could put on wheels and pull with a car.” 442 F.2d at 1153-1154.
Since we have decided that the portable welder towed by the appellant was not designed for use with a private passenger automobile, we do not have to reach the further question raised by the appellant as to whether his pickup truck was a “private passenger automobile.” Even if the portable welder was, in fact, being used with a private passenger automobile, under the terms of the policy the welder was covered only “if designed for use with a private passenger automobile,” and we have held it was not so designed.
Judgment affirmed. Costs to respondent.
McQUADE, C. J., and McFADDEN, and BAKES, JJ., concur.