The typeface is a solid serif, with too much graduation that treads the well worn path of uppercase serif font and a coat of arms, good use is made of the differing lengths of the text to bring the elements closer and play against each other, creating a tightly integrated block.
The guillotine shape acts offsets the overall block effect, and is mostly used as a tab at the top of a typical design; slightly more difficult when bleeding to the edge is impractical, but a keyline device is then used to define the shape.
There is a rather lovely illustration of the coat of arms and explanation in a heritage guide to the history of the institution. The version rendered in the logo is in a clear linear style that benefits from being displayed large, but can cope with the inevitable reductions.
A common problem with universities – they have a tradition that they would like to refer to, but would also like to present some dynamism and development. Heriot Watt have chosen a device to give the restrained and somewhat conservative logo some tension.