Around 1914 McLean joined the Belfast Banking Company and served as a cashier. He worked in Sligo branch.
He enlisted at the outbreak of the Great War serving initially with the North Irish Horse and as a Corporal was selected for a commission. In 1914 he was appointed as a Temporary Second-Lieutenant with the 4th Brigade of the Royal Field Artillery.
On 22nd April 1916 a report in the Coleraine Chronicle detailed the contents of a letter from McLean to the Reverend J Bell B.A. In it, he states “Since writing you we have been engaged in a few ‘scraps’. The Germans have been more or less active along the whole line. T o capture a wood directly on our front line they made a bold movement, and gained some ground, which they held. The wood at this point was very dense, and the infantry work rather difficult, so the job was given to us. We were delighted, and after giving out infantry time to take cover, we opened fire. On this occasion I was given the observation work and the direction of the fire. The fire was kept up until the position was made too hot for the enemy. The system of fire adopted in this case was to swing the guns about from one place to another, so as not to give the enemy any chance of fortifying any particular point. The guns were next concentrated on the front of the wood, and by gradually increasing the range, swept to the opposite end. Our infantry at this time crept up under the shadow of our fire, and when daybreak arrived we were in full possession of the wood, which we still hold. The fight as far as we were concerned was purely sport, as the men are never happier than when the guns are in action. The French artillery may not be quite so accurate as ours, but their speed is terrific. I have had the honour to visit and lunch with officers of the French battery. On that occasion, when I was being shown around, the commanding officer ordered the gun into action. About a dozen men leapt from a dug-out, and twelve rounds were fired in less than half-a-minute. The gun used was the famous “75” which we read about in connection with the Verdun battle. The artillery of both sides, in this case, played a great part, and when the great day arrives you will find the lion’s share of the fight will rest with the artillery. If possible we always have church service every Sabbath morning in a dug-out, and all are keen to attend. It is a very full house, our Commander-in-Chief, Sir Douglas Haig, being very strict on this point. I have had the unusual experience of having to leave the service and take eight men with me, owing to the guns being ordered into action by a telephone message”.
The London Gazette reported on 26th September 1916 that McLean had been awarded the Military Cross (MC). The citation reads:
“For conspicuous gallantry in action. He attempted to save a wounded gunner from a burning gunpit, and successfully saved the gun. During an attack he led two platoons of another unit over the parapet, and handed them over to their officer, who was rallying his men in the open. On another occasion he fought a single howitzer with great determination for seven days under heavy shell fire, although himself wounded.”
He was serving with the 9/148 Brigade Royal Field Artillery as a 2nd Lieutenant when he was killed in action on 30th September 1917. This was reported in the Coleraine Chronicle of 13th October 1917. The Belfast News Letter of 13th October 1917 reports:
The Coleraine Chronicle reports on 19th January 1918 that Lt. McLean’s Military Cross was presented to his relatives at a presentation ceremony.
McLean is buried in Kemmel Chateau Military Cemetery, Heuvelland West-Vlaanderen, Belgium.
He is mentioned in ‘Bushmills Hero’s 1914 - 1918’ by Robert Thompson, Coleraine, published privately, 2003 (2nd edition). His name is sometimes spelt MacLean.