Ok so page 20 of (I think armada, it's a PDF I have called BFG Imperial fleets from 2011) It says (I'm paraphrasing) the discussion about SM fleets post Heresy, including Gulliman and Corax, reached a compromise which limited the space marines to vessels whose primary role was that of transport, delivery and suppression designed to facilitate planetary assault.
I thought it said that they designed a new craft to fulfil this role so ill make you right 
The full text of the section is below. As intercepta says, there is no mention of new designs so its still possible that the M41 style battle barges and strike cruisers existed at the time of the Heresy. Per the Codex Astartes, space marine chapters would be (mostly...) limited to a few specific designs that probably already existed. Plenty of planetary invasions happening in the Great Crusade, so designing a ship (battle barge) specifically designed for planetary invasions is not out of the realm of possibility.
"When Gulliman set about the long and arduous task of preparing Codex Astartes, the role of
space vessels amongst the Adeptus Astartes proved a particular sticking. For an Imperium
still reeling from internecine Heresy that almost tore it apart, the division of power was a vitally
important consideration. Of the most extreme options on offer, it was ventured by some that
the Space Marines should be denied any vessels at all, barring intra-system transports for
movement between homeworlds and attendant moons.
Corax, amongst others, protested strongly that in fact had the Space Marines been
better equipped with fleets of their own his own Legion might not have been so horrendously
decimated when trapped on Istvaan V by Horus and the newly revealed traitors. Instead, a
compromise was reached which limited the Space Marines to vessels whose primary role was
that of transport, delivery and suppression designed to facilitate planetary assault. Only the
smallest of vessels would be permitted to act exclusively as gunships, with the larger
battlebarges and strike cruisers remaining predominantly as aids to invasion, ensuring the
Space Marines would never present a threat to the Imperial Navy proper. Inevitably, the
wrangling over interpretation of a ship’s ‘primary role’ leads to some chapters
possessing rather more versatile fleets than the Imperial Navy is entirely comfortable with."
