Bute Docks at Cardiff
1839 Increasing agitation for proper dock facilities led Cardiff's foremost landowner, John Crichton-Stuart, 2nd Marquess of Bute, to promote the construction of the (West) Bute Dock, designed by Admiral William Henry Smyth which opened in October 1839.
1841 Just two years later the Taff Vale Railway was opened, following much the same route as the canal.
1855 Construction of the new East Bute Dock from 1855, built by Thomas Cubitt's firm,
1850 Opening of the new dock resulted in coal supplanting iron as the industrial foundation of South Wales, with exports reaching 2 million tons as early as 1862.
The Cardiff Railway came into being to service Bute Docks, to provide facilities for the traffic to and from the Docks. The railway was only 11 miles in length, a fact which belied its importance, since it provided both the Taff Vale Railway and the Rhymney Railway, inter alia, with access. 
1886 The Bute Dock Company was incorporated to take over properties from the late Marquis of Bute.
By 1906 the Bute Docks comprised the following: Bute West Dock — Entrance to basin, 45 feet wide; basin, dock area 18 acres; Bute East Dock — Sea lock, 220 feet long by 55 feet wide; Roath Basin — Dock (area 12 acres); Roath Dock — Inner lock, 600 feet long by 80 feet wide; dock area 33 acres; New South Dock — Lock 850 feet long between inner and outer gates by 90 feet wide; dock area 50.5 acres. See 1906 Institution of Mechanical Engineers: Visits to Works.
Bute East Dock and West Dock lay roughly north-south, and terminated close to the city centre by Tyndall Street. The north west corner of West Dock had a connection to the Glamorganshire Canal. This canal connection passed under Bute Street and under the railway line, with lock gates immediately east of the railway bridge. The branch is now filled in and the former canal bridge is now used by pedestrians (see photo).
West Dock in turn was connected to the East Dock by a narrow canal which entered near its north west corner. The West Dock has long been filled in, and is marked only by a grassed area and by a large hydraulic ram placed on a concrete plinth (see photo).
The north east corner of West Dock was fed by a feeder canal supplied from a weir on the River Taff. The feeder can still be seen inplaces, and carries flowing water. Stone-clad warehouses have survived at the north end of West Dock, converted to flats, but otherwise the area is devoid of character.
East Dock survives as a water feature. It was originally dominated by coal staiths, but there were also graving dock (called Hill's Dry Docks on the 1901 O.S. map). There were also coal staiths on the east side of West Dock, and all were served by railway lines, one branch of which came over Bute Viaduct. The original owner of the lines was the Taff Vale Railway. The line serving West Dock terminated at the Docks Station, and it was at this location that the TVR had their cramped locomotive works and also a dock on the Glamorganshire Canal.
Sources of Information
-  Wikipedia
- The Stock Exchange Year Book 1908