Leighton Phillips, of Market Drayton, was today sentenced for touching two girls, aged 11 and 14, on a train out of Cardiff Central Station on February 1 this year.
Sentencing him Judge Paul Thomas QC said the former constable, of Forest Road, had shown no remorse over his actions. He was convicted following a trial in Swansea last month after denying the offences.
He told Phillips: "Your behaviour on that train following the rugby match in Cardiff was a disgraceful episode for any adult man let alone a serving police officer.
"The reason your are in this position with your cherished career in tatters is that you simply had too much to drink. You had drunk 12 pints of beer and all of that was consumed by 5pm that afternoon. It was that drunkenness that led to you behaving in that appalling manner.
"You were so drunk that you started touching the legs of two girls who were near you on the train and that caused them distress and embarrassment.
"Throughout this proceedings you have shown no remorse.
"The only thing you have shown is arrogance. Arrogance on the train, arrogance when you were arrested, when interviewed by the police and arrogance during the trial. The final arrogance is in the pre-sentence report where you say, 'they have to realise the impact that their complaint has had others'."
He said that throughout the proceedings the defendant, 34, had been unable to look him in the eye.
Judge Thomas added that while he accepted he had worked hard to obtain his dream job in the force, he was "wholly unsuited to be a police officer".
Mr Talbir Singh, on behalf of Phillips, said: "As a consequence of the conviction and sentence of this matter this is a man who has lost his job and good career."
Judge Thomas told the hearing in Swansea that he did not believe a custodial sentence was required.
For sexual assault Phillips, who served in Market Drayton, was given a concurrent two-year community order, he must attend 20 rehabilitation activity days, and was made subject to an electronically tagged curfew between 10pm and 7am for three months.
He will also be subject to notification on the sex offenders' register for five years. There was no order for costs.
Following a West Mercia Police misconduct hearing Phillips was barred from ever rejoining the police service. The hearing concluded that he would have been immediately dismissed for gross misconduct had he not already resigned from the force on October 1.
The force's head of Professional Standards, Superintendent Rebecca Love said: “There is no doubt that Phillips’ actions have fallen far below the standards we, and quite rightly the public, would expect and as a result he will be placed on the College of Policing Barred List and will not be employable within the UK Police Service.
“The public must be able to have trust and confidence in the police service to uphold the law, and where behaviour undermines this, either on or off duty, I would like to offer my assurances to members of the public that appropriate action will be taken.”