Historical background
In 1924, Blue Circle (not yet called that) was at a climactic point in its history. After its near-fatally unsatisfactory launch in 1900, APCM had lumbered onward through the first decade of the twentieth century - a period of depressed market. From 1911, the market had started to pick up, and APCM was able to declare its first dividend in 1913. In 1911, a partial re-organisation accompanied the formation of BPCM. Some of the grizzled old members of APCM's board were ousted, while a cohort of "new men" arrived, notably the Cambridge group (centred on Stewart and Davis) and the Earles from Hull. These were initially corralled within BPCM, which they proceeded to organise on distinctly different technically-oriented lines. By contrast, the APCM philosophy was a) that everything to do with cement manufacture was already known, and b) that they were the sole repository of that knowledge.
Just as the market took off in the second decade, the Great War broke out in 1914, and everything went into suspended animation for four years. Development projects were shelved, and most of the more labour-intensive plants were shut down. Emerging from the tunnel in 1918, the Board faced two major decisions:
- A post-war boom was expected, and it was necessary to decide how much of the by now decrepit old capacity to re-instate, or whether indeed it would be better not to meet demand, and maximise profit for a few years.
- The "new men" were convinced that the major plants, hurriedly expanded (at great expense) by APCM in its early years, were now hopelessly out-of-date, and should be re-built, preferably from scratch.
Suffice it to say that the "new men" narrowly carried the day, and it was decided to re-build Bevans and Swanscombe. Bevans was shut down for a re-build - lasting 5 years - in 1921. Apart from the brief post-war boom, the loss of this capacity necessitated re-commissioning many inefficient old plants for a short time. This was a humiliation for the "old guard", and particularly for APCM's promoter, O'Hagan, who resigned from the Board and left the industry in 1921.
In 1923 the febrile atmosphere of the company was further disturbed by the acquisition of a large proportion of the company's shares (with, of course, borrowed money) by Henry Horne. By 1924, he had control, and was able enforce a reorganisation of the Board. Stewart and Davis moved into controlling positions, while the influence of the old guard, and particularly the Whites, evaporated. Henry Horne had planned to sell-on his holdings, and his prospective buyers backed out, so Horne went bankrupt and stood down. But his changes remained in place - presumably because the new order was a natural move, and needed only a disruptive intervention to precipitate it.
The 1924 Plant Schedule
In early 1924, a "snap-shot" of the entire equipment of the two companies was obtained. It is tempting to assume that the prospective take-over was the main reason for the survey. Although I am unaware of the details of its planning, from its format it can be seen that it was centrally devised, using a standard pro-forma, and a set of instructions, but the information was supplied by the individual plants, with the inevitable variability in the interpretation of the instructions. The format and scope closely follows the production- and cost-reporting regime already established within BPCM by A. C. Davis. The text of the surveys is given in separate pages for APCM and BPCM.
The company in 1924 was as follows:
- Clinker production at Bevans had ceased.
- No new plant had been installed since before the war, other than a few pre-war projects that had been in abeyance (such as kilns at Johnsons and Wilmington) and two recent plants (Kent and Humber) that had been bought following the failure of their promoters, so the company was essentially that of 1914.
- Many ancient "zombie" plants briefly revived after the war were still "on the books" although in the process of demolition.
The report therefore gives a valuable picture of what is essentially the pre-WWI industry, just before most of it disappeared, replaced by an industry organised on more modern lines. However, the data are highly defective and considerable effort is required to interpret them on a technically-valid basis.
Completeness. In many reports, sections are missing. This may simply be because pages have been lost, but in many cases it is clear that sections were ignored by some plants. There is a distinct difference between APCM and BPCM plants, the latter mostly being characterised by a more conscientious approach. In some instances, missing information can be interpolated from other sources, but often a lacuna remains.
Dimensions. The dimensions of plant, and in particular washmills, ball mills, tube mills, kilns, coolers and coal driers, are important in order to compare and contrast plants and to pin down design principles. Dimensions were required as a standard part of the report, and the basis of measurement was presumably defined in the instructions, but the data actually presented was so undisciplined that no item of data can be accepted un-critically. In particular, although the large majority of the plant was of foreign origin and built to metric dimensions, they are rendered in imperial without precise conversion. The impression one gets is that the dimensions were actually unknown, and apparently of no interest. So it's necessary to ascertain whether a dimension is outside shell, inside shell or inside lining (this being almost never stated) and, in the case of metric equipment, what the true value was.