Strong bricks used for added strength and resistance in civil engineering.
""fire-clay brick that has a dense and strong semi-vitreous body and which conforms to defined limits for water absorption and compressive strength""
—British Standard ISO 6707-1;2014 (taken from wikipedia)
Growing up in a city built on industry, I was very familiar with this type of brick. Some red, some blue, (and, as I recall, some yellow) used in building railway viaducts, factories, even in housing for a damp-course above the foundation. These bricks are less porous, usually fired to a higher temperature (especially the blue bricks, fired at extremely high temps). They are denser than normal bricks, glass-glossy and used where resistance to water or pollution-derived chemical attack is required. Consequently they were all over Nottingham in railway building, bridges and factories, part of my growing up, of my landscape.¹
In my mind they have a strange beauty, dark and heavy yet shining in the (admittedly, rare sunlight) when new, or dark-patina'd thanks to a century of coalsmoke pollution. They added gravitas to my childhood landscape throughout the older parts of the city and sometimes I even dream of them, part of those dark, satanic mills that grew out of industrial revolution. Even in the city centre, older buildings would have the heavy, dark engineering bricks as part of the dampcourse, contrasting the glowing bright orange of the native Bunter sandstone building atop.
I dedicate this to the memory of WIlliam Marshall, a civil engineer friend of mine, who sadly died following a serious fall, suffering a broken pelvis.
¹ Hazelnut says re Engineering brick: The biggest retaining wall on a railway line in Europe in High Wycombe, where I grew up, is made out of these, most likely…Also have a C! for proper Dull Men's Club energy.
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