JUDGMENT R.L. Khuraua, J.—The abovementioned First Appeal and Cross-objections arise out of the award dated 6-8-1984 of the learned Motor Accident Claims Tribunal (I) Solan and Sirmour Districts at Nahan, and are being disposed of together by this single judgment. 2. Bus bearing No. HPA1207 belonging to the appellant-Corporation hereinafter referred to as the Corporation and which was being driven at the relevant time by the driver Narayan Dass met with an accident on 2-11-1983 near village Dingri at about 8.15 a. m. In the said accident one Lavinder Singh son of Mata Ram a passenger of the said bus was killed. A number of other passengers also sustained injuries 3. A petition under section 110-A, Motor Vehicles Act, 1939 was filed by the parents, widow and minor children of the deceased Lavinder Singh, hereinafter referred to as the claimants, claiming compensation of rupees three lacs for the death of the said deceased. It was pleaded that the accident had occurred as a result of rash and negligent driving on the part of the driver of the Corporation. 4. The parents of the deceased Lavinder Singh, namely, Mata Ram (father) and Smt. Gadola (mother) died during the pendency of the present appeal and their names were ordered to be deleted from the memo of parties, since their legal representatives were already on the record as respondents 3 to 5 in their own rights 5. The Corporation while resisting the petition, set up the plea that the accident was as a result of sudden mechanical defect and not as a result of the rash and negligent driving on the part of the driver, ft was further averred that as per the claimants own showing, the bus at the relevant time was not being driven by the driver, but by some unauthorised person 6. The learned Tribunal came to the conclusion that the accident has taken place as a result of rash and negligent driving on the part of the person who was driving the bus. A total compensation of Rs. 72,120 was, therefore, awarded in favour of the claimants in respect of the death of the deceased Lavinder Singh 7. The Corporation feeling aggrieved by the findings of the learned Tribunal have come up in appeal before this court. A total compensation of Rs. 72,120 was, therefore, awarded in favour of the claimants in respect of the death of the deceased Lavinder Singh 7. The Corporation feeling aggrieved by the findings of the learned Tribunal have come up in appeal before this court. It is contended that the Tribunal has misread the evidence and has come to a wrong conclusion that the accident had taken place as a result of rash and negligent driving on the part of the driver. It has further been contended that even otherwise the amount of compensation has been assessed on a higher side and that the learned Tribunal has failed to adhere to the well settled principles while assessing the amount of compensation. 8. The claimants, who also felt aggrieved by the award of the learned Tribunal has come up before this court by way of Gross-objections challenging the assessment of compensation in their favour. It is contended that compensation has been assessed on a lower side and that the claimants were entitled to the compensation of Rs. 3,00,000 as claimed by them, 9. We have heard the learned Counsel for the parties and have gone through the record of the case. 10. In so far as the question of negligence on the part of the driver of the bus is concerned, it is significant to note that vide the impugned award dated 6-8-1984, four claim petitions pertaining to different claimants were decided holding the driver of the bus to be rash and negligent and responsible for the accident. No appeals have been filed by the Corporation against the award in so far as the other three set of claimants are concerned. Failure on their part to challenge the findings of the learned Tribunal qua the negligence on the part of the driver in the other cases would operate as res judicata against the corporation and would estop them from challenging the findings of the learned Tribunal with regard to the negligence of the driver. [See : Haryana State v Sudesh Raizada and others 1991 ACJ 54], 11. Even otherwise there is sufficient evidence on the record to show that the accident had taken place as a result of rash and negligent driving on the part of the driver who was driving the bus at the relevant time. Ext. [See : Haryana State v Sudesh Raizada and others 1991 ACJ 54], 11. Even otherwise there is sufficient evidence on the record to show that the accident had taken place as a result of rash and negligent driving on the part of the driver who was driving the bus at the relevant time. Ext. P-3, is the report of the Committee constituted by the District Magistrate, Sirmour to inquire into the cause of accident. This Committee after verification of the facts came to the conclusion that the bus at the relevant time was not being driven by its regular driver Narayan Singh, but was being driven by one Dalip Singh, Inspector of the Corporation. The Committee also came to the conclusion that there was no mechanical defect in the bus and that the accident was as a result of rash and negligent driving on the part of the person driving the bus, 12. It is well established principle of law that when the owner of the motor vehicle involved in the accident comes up with the plea that the accident was as a result of some mechanical defect, the onus is heavily upon him to plead and prove such mechanical defect and that the defect was so latent that it could not be discovered inspite of due care and precaution. Besides, the owner is required to plead and prove that the vehicle was kept roadworthy by periodical mechanical inspection. In the present case, neither there are pleadings nor evidence to show that the bus was kept roadworthy by periodical mechanical inspection and that the defect was so latent that it could not be detected inspite of due care and caution. 13. The learned Tribunal, therefore, on the basis of the material coming on the record has rightly come to the conclusion that the accident had taken place as a result of rash and negligent driving on the part of the driver of the bus. 14. Coming to the question of the amount of compensation payable to the claimants, the learned Tribunal has assessed the monthly income of deceased at Rs. 400 per month and after giving au allowance of Rs. 80 towards the personal expenses of the deceased, had assessed the dependency of the claimants at Rs. 320 per month, that is, Rs. 3,840 per annum. A multiplier of 18 was applied and compensation of Rs. 69,120 was assessed. 400 per month and after giving au allowance of Rs. 80 towards the personal expenses of the deceased, had assessed the dependency of the claimants at Rs. 320 per month, that is, Rs. 3,840 per annum. A multiplier of 18 was applied and compensation of Rs. 69,120 was assessed. To this amount, the conventional amount of Rs. 3,000 towards loss of expectation of life was added and total compensation of Rs. 72t120 came to be awarded in favour of the claimants. 15. The deceased was of about 29 years of age at the time of his death. He was working on a daily rated basis. According to the claimants, besides working on daily rated basis, he was also having an agricultural income. 16. Nothing has come on record to show the extent of land owned by the deceased- Admittedly, the father of the deceased was alive at the relevant time. The land, if any, was, thus, owned by his father and not by the deceased. In the absence of specific evidence as to the income of the deceased, the learned Tribunal has taken the monthly income of the deceased at Rs. 400 as has come to be suggested by the Corporation during the course of evidence, and, such findings of the learned Tribunal do not call for any interference. 17. We are satisfied that the learned Tribunal has rightly allowed a deduction of Rs. 80 per month on account of personal expenses of the deceased by taking the total unit of the family as 10 while assessing the dependency of the claimants at Rs. 320 per month, that is, Rs. 3,840 per annum. The learned Tribunal has also by taking into consideration the age of the deceased and that of the claimants, applied a multiplier of 18 correctly. The compensation of Rs 72,120 has, therefore, been rightly assessed by the learned Tribunal, The assessment so made by the learned Tribunal does not call for any interference, 18. Consequently, both the appeal being F. A. O. (MVA) No. 223 of 1984 and Cross-objections No. 55 of 1985 are dismissed, leaving the parties to bear their own costs. Appeal dismissed.