• Thomachen had his studies in St Berchaman's High School. He was very intelligent in studious and  his favorite subject was  Mathematics. While in third form and in matriculatation, he won state scholarships. He passed Intermediate from CMS College, Kottayam and BA   from Maharajas College, Trivandrum.  He passed LT in 1932.
• He taught in St. Berchmans high school for one year and later joined the teaching department in St. Aloysius College,Quilon on 5 July1926 and served there for 38 years till retirement.
• In between, during 1936-37 he worked as Headmaster in a lower grade training school. 
• Thomas Sir, a six footer with fair complexion, graceful face and pleasing  behavior remained as a adorable  teacher both among staff and students. He used to be an active person in thel cultural activities of the school, as well.
• He was very close to Jerome Fenandez, Bishop of Quilon and as desired by the Bishop ,he stayed in a house built in Bisho'sp palace .He remained unmarried and involved in many social activities.
• Another area where Thomas Sir devoted his time most was in co-operative movements .He was committee member, secretary, president of almost 8 co-operative societies.
• His major achievements were as below:
• Construction of 22 houses in 1930 for economically backward people was another feather in his cap. . His excellence Chithira Thirunal Maharaj once visited and appreciated this noble venture. He was instrumental in building 50 houses for industrial workers in 1952 and in constructing of 22 houses in 1930 for economically backward people .  Houses for fishermen when their dwelling got gutted in his capacity as president of St. Thomas Co-operative Society. As President in Quilon Taluk Costal Development Bank, constructed 40 houses for fishermen in coalition with Fisheries Department. He was the President of this Bank for 12 years. In his leadershipConstruction of 22 houses in 1930 for economically backward people .. As President in Quilon Taluk Costal Development Bank, constructed 40 houses for fishermen in coalition with Fisheries Department. He was the President of this Bank for 12 years.  houses for fishermenwere built when their dwelling got gutted .. As President in Quilon Taluk Costal Development Bank, constructed 40 houses for fishermen in coalition with Fisheries Department. He was the President of this Bank for 12 years.

He along with Prof O.C. Varghese amd O.V. Varghese formed the Olasail Kudumbam Sanghadena and he was the President for many years and was instrumental in raising a capital fund for the Sanghadena. It was Thomachen who donated the first Golden Cross (Ponnum Kurisu) to Changanacherry Metropolitan Church.

In 1975, he left Quilon and for the rest of his life he stayed with his younger brother Kunjachen. Slowly his health deteriotated and Mar Jerome Fenandez, former Bishop of Quilon and Mar Joseph, Bishop visitied ailing Thomachen. On 11^th April 1990, he was called for eternal rest.