Irene,
You can get copies of the War Diaries but it will not be cheap. I have similar for a RAF Squadron and obtained them on CD, but you are probably talking a few hundred dollars.
My interest starts when my grandfather joined the Regiment in May 1944, so please forgive the lack of information prior to that point. John Henry Hipkins (aka 'Jack') had been Coastal Artillery, but the need for Coastal gunners diminished as the war dragged on and he was re-rolled as an AA Radar Operator. You are probably aware that the 115th Heavy Anti Aircraft (HAA) Regiment was a Territorial Army unit raised for service in the war. It was equipped with the excellent British QF 3.7 inch (94 mm) Anti Aircraft gun, primarily used in the Anti Aircraft role but also capable of engaging ground targets using High Explosive air and ground burst munitions. Broadly speaking the Regiment consisted of a Regimental Headquarters and 3 Batteries (numbered 361, 365 and 367) and like most HAA Regiments at the time was controlled at a very high level i.e. they were Army or Army Group troops and were very rarely commanded by any smaller formation. They used the Tactical Number of ‘169’ on all their vehicles.
The Regiment moved to the Southampton area in May 1944 as part of 74th Anti Aircraft Brigade (AA Bde). They came under temporary command of Southern Command and Regimental Headquarters (RHQ) was located at a house called 'The Walls' in Nursling. In preparation for a deployment to the Continent, all ranks were recalled to the unit on the 3rd August 1944. A total of 36 Officers and 910 Other Ranks (ORs) embarked at the port of Tilbury on the 9th. The ships they boarded were 'SS Ignatius Donelly' (carrying the CO, Adjutant, part of RHQ and 361 Battery), the 'SS Robert Heize' (carrying 365 Bty, part of RHQ and the Royal Electrical and Mechanical Engineers (REME) Detachment) and the ‘SS Ocean Strength’ (carrying 367 Bty). The vessels anchored off the town of Graye-sur-mer, Normandy on the 12th and landed across Juno Beach on the 13th of August. On the 26th of the month they were in action around the town of St Julien. On the 29th they came under command of 107th AA Bde, part of 1st Canadian Army, 21st Army Group and were employed in the AA role defending the Normandy beach head. Like most units at this time, they moved around quite a lot, but at various times they defended Caen and were in action around Falaise. With the break out from the beach head in late August, they moved into Belgium and by the 21st of September were in action around Antwerp. At this stage of the war, the Regiment was being used in a dual role; engaging both air and ground targets (the latter mainly in support of Canadian formations). An extract from the War Diary dated 3 Oct 1944, states: “Since the Regiment has been in their present location there has been increasing requests for the engagement of targets by HAA both by Field Artillery and Infantry. Tasks that have been accepted and successfully engaged have been; Harassing Fire, Counter Battery, Barrage, O.P. controlled both by ground and air O.P.” (O.P. standing for Observation Post). Throughout the remainder of the year they were fairly static in Holland and when one understands the operational and tactical situation at the time you can understand why. The following is a transcription of the War Diary and gives a flavour of what they were doing and where: