Ipswich was becoming a major inland port and was located at the intersection of important transport routes to the Darling Downs and Upper Brisbane Valley.

However, a portion of the line between North Ipswich and Wulkuraka was retained to service the railway workshops and also for the use of coal mining and coke manufacture that were then occurring at Mihi Creek.

[1] The discovery of coal in Queensland dates from 1825 when outcrops were observed by Major Edmund Lockyer on the banks of the upper Brisbane River.

The following year, explorer Allan Cunningham also marked several outcrops on the Bremer River on his survey map for New South Wales Governor Ralph Darling.

[2] This has led to no systematic record keeping of coke manufacture in Queensland - especially concerning production numbers, value, equipment used, people employed, or any other detailed characteristic.

Coke is used as both a fuel and as a reducing agent in smelting ore and is produced from baking bituminous coal in ovens at temperatures as high as 2,000 °F (1,090 °C).

Coke manufacture became an important extractive industry from the late 1860s with the introduction of mechanically driven transportation, such as steam- powered ships and trains.

[2] Coke ovens erected on the West Moreton Coalfield were exclusively of the beehive type, so called because of their domed appearance.

The space between ovens was usually filled with rubble and earth to provide insulation and the whole battery surrounded by a stone retaining wall to resist the outward thrust of the brick domes.

The Mihi Ovens remained in use until 1890/1 when Wright's attention was diverted a new coal development at the New Bishop Mine located nearby.

[3] He named his venture the Francis Mine, constructed a horse whim for hauling loaded coal skips out of his tunnel, sank an air shaft to the workings and erected bunkers of "60-tonnes capacity".

[1] In 1923 Francis sold the site to a partnership of miners and a barrister who created and floated the company, Klondyke Collieries Limited.

[1][2] In 1948 the site changed hands again and was renamed Moreton Colliery and worked until the early 1950s when the pit's supply was exhausted.

[1] The Mihi Creek heritage site is located at North Ipswich in a grassy expanse of broken, undulating land that slopes down to a bend in the Bremer River.

Both sets of embankments run in arcs which are roughly parallel to the curve of the bank of the Bremer River to the south.

A number of blocks are also located at the south western corner of the site near where the smaller embankment crosses a gully.

From the piles removed, it was noticed that these had sharpened ends reinforced with strips of cast iron and matched the description given for the bridge in the original design drawings.

The space between each oven would be filled with earth or rubble for insulation, and evidence of compacted orange clay was recorded in DERM during test excavations in the area.

[1][6] A short section of rail line of unknown date or origin and passing through a small cutting is extant in the vicinity of the coke manufacturing site on Lot 5 on AP3320.

The very need for the railway reflects a government desire for faster, reliable and more economic transport to and from the region to promote commerce, industry, growth and settlement.

Coke manufacture played an important though under-recognised role in early coal mining and related industries over an extended period of time (1870s - c. 1960).

The Mihi Creek site includes archaeological artefacts which illustrate early examples of processes and activities relating to the increasing demand for quality coke for use in early Queensland industry in the late 19th century (particularly for rail and maritime industries and coal-powered engines generally).

This area has potential to provide further information about the construction of rail formations and embankments at the inception of the State's railway development.

Subsurface remains would feature high integrity due to lack of disturbance since the cessation of coke manufacture in c. 1960.

[1] While the colliery and coking operations at Mihi Creek were one of a number of the type within the West Moreton Coalfield, they were also one of the longest running (1870s - c. 1960) and underwent significant change over time, including owners and potentially equipment and production techniques.

Archaeological investigations have potential to reveal important information about specific operations at Mihi Creek, particularly the full extent of coal mining and coke manufacture, the types of equipment used (other than beehive oven type and probable number in the original battery), and the precise location of key features.