The principle of 'equal pay for equal work' is applicable when employees holding the same rank perform similar functions and discharge similar duties and responsibilities but are treated differently. However, when there are significant differences in the qualifications, duties, and responsibilities of two categories of employees, they cannot be treated as equal for the purpose of pay scales.

Devinder Gupta, J.-Learned Counsel for the parties state that decision in Civil Writ Petition No. 421 of 1987 will also decide the fate Of the other four petitions. Consequently, we propose to dispose of the aforementioned five Writ Petitions by this common judgment. However, reference here-under is being made to the facts in Writ Petition No. 421 of 1987.

2. Petitioner-Board constituted under the Indian Electricity (Supply) Act, 1948 has number of Power Projects, one of which is located at Shanan in Jogindernagar of District Mandi, Himachal Pradesh known as Shanan Power House. Respondents No.1. to 12 have been working as Machine Attendants and Assistant Machine Attendants. There has been revision of pay-scales applicable for numerous categories of employees of the petitioner-board effective from 1-1-1978. Respondents felt aggrieved due to the alleged anomalies in their pay-scale. Prior to 1-1-1978, Machine Attendants and Assistant Machine Attendants were in the pay scale of 130-5-150/6-190/10-210 and) 10-4-122/5-142/6-190, respectively. The Machine Attendants claimed that they had been performing the duties like Auxiliary Plant Attendants and ought to have been put in the pay-scale of Rs. 700-1200 instead of Rs 400-600 and consequently the Assistant Machine Attendants also ought to have been put in the higher pay-scale admissible to Junior Plant Attendants. A dispute was raised. The State Government through Notification dated 4-3-1985 referred the following dispute to the Industrial Tribunal:— Whether there are anomalies in the pay scales revision of the machine attendants/assistant machine attendants of the Shanan Project of Punjab State Electricity Board at Jogindernagar, District Mandi (H. P ) with other category of workers, If so, the relief, the workers are entitled to in this respect."

3. The Respondents filed their claim Annexure-F before the Industrial Tribunal. The reply to this, Annexure-G was filed by the petitioner. The Tribunal formulated the following issues for determination on 6-10-1985: "1. Whether there are anomalies in pay-scale revision of the machine attendants and assistant machine attendants of the Shanan Power House of the Punjab State Electricity Board, Jogindernagar vis-a-vis other categories of workers. If so, to what scales of pay, the petitioners are entitled to? (OPP)

2. Whether this Tribunal has no territorial powers to entertain and answer this reference ? (OPR)

3. Relief."

4. After recording Sndings the Tribunal made its award Aonexure P on 5-4-1987 The Tribunal held that there were anomalies in the grant of pay-scale to respondents No. 1 to 12 and concluded that Machine Attendants were entitled to the pay-scale allowed to the category of Diesel Engine Drivers and Assistant Machine Attendants to the pay-scale allowed to the category of unqualified diesel Engine Drivers, namely, Rs 700-1200 and Rs. 600-1200, respectively w e. f. 1-1-1978. Issue as jurisdiction was not pressed before the Tribunal. It is this award made by the Presiding Officer of the Industrial Tribunal, Himachal Pradesh, which is under challenge at the behest of the petitioner-Board.

5. The main basis for the challenge to the Award is that the conclusions reached by the Tribunal are entirely arbitrary and perverse. The Tribunal assumed an erroneous fact that diesel engine drivers, both qualified and unqualified, were in the same pay-scale prior to 1-1-1978 as that of the petitioners. Due to this erroneous assumption, the entire award is vitiated. There is no basis for coming to this erroneous conclusion.

6. It is the petitioners case that with effect from 20th February, 1973, there had been revision in the pay-scales of Diesel Engine Drivers. Those holding diploma with three years experience in the line of Diesel Engine Operation or Matriculation with I. T. I in the trade with minimum experience of five years were put in the scale of Rs. 200-10-250/270-15-450. Due to this revision in pay-scale, two categories of Diesel Engine