Nelmes was an outstanding front-row forward who won six caps for his country between 1975 and 1978, making his debut against Australia in Sydney and his final appearance against New Zealand at Twickenham.
He played with great distinction for the Bristol and Cardiff teams of that era, captaining the latter and also appearing for the Barbarians against the British Lions and New Zealand.
"Barry was a great servant of great Bristol and Cardiff teams, leading the latter with distinction and playing a part in their famous victory over Australia in 1975.
"He was a distinguished and versatile performer for England in the 1970s and deserves to be recognised as one of a superb group of front-row forwards who played in that era."
Nelmes, born in Bristol in 1948, was one of an outstanding generation of props and it was only the presence of one of England's all-time greats, Fran Cotton, that prevented him from making more appearances for his country.
"Barry was probably the first of the new breed of prop forwards," said his Bristol and England team-mate John Pullin.
"Until then the role of the prop was to push and squeeze but Barry was useful around the pitch being equally skilled with ball in hand."
Nelmes, who lived in the Welsh capital, was a backbone of the Blue and Blacks' pack in the 1970s and also became the first Cardiff club player to be capped by England.
Originally from Bristol, where he attended Portway Secondary School he represented England Schools (U15) against Wales at Twickenham in 1963.
At the time he was playing lock but was equally at home at No 8. His natural mobility and ball handling ability stood him in good stead when he transferred to loose-head prop in senior rugby.
At 6'2" and 17st he was ideally built for the modern game and made rapid progress through the representative ranks.
Having made his first-class debut for Bristol as a 16-year-old he was selected two years later for the Western Counties XV that beat the touring Wallabies. In later years he also turned out for the Combined Team against the All Blacks and Springboks.
Nelmes joined Cardiff in 1973 and packed down with current Wales team manager Alan Phillips and Mike Knill in an outstanding front row that was the platform for another famous club triumph over the 1975 Wallabies.
In the summer of the same year he had flown out to Australia as a replacement and won the first two of his six caps for England.
His first "home" international was in 1978 against Wales. In the same pack was another Cardiff legend, John Scott, then with Rosslyn Park, while the opposition included club-mates Gareth Edwards and Gerald Davies.
Having been vice-captain for two seasons he succeeded Davies as club captain in 1978-79 and went on to play 166 first team games for Cardiff.
He also played for the Barbarians in two particularly prestigious fixtures - the historic Queen's Silver Jubilee match against the Lions at Twickenham in 1977 and, the following year, as a replacement against the All Blacks at the National Stadium in Cardiff.

Barry is pictured with Fran Cotton during the 1978 five nations game Vs Ireland.