Industrial archaeology
Designer Ronald Maddox, who had previously designed stamps, produced drawings of four striking structures that have been characteristic of Great Britain's industrial development. He created designs for a series of vertical stamps and a block in which the stamps were depicted horizontally. That he sometimes took some liberties in doing so only became apparent upon viewing the structures.
Towanroath Shaft Pumping Engine House, Cornwall
The 27p stamp depicts the ruins of the engine room and boiler house of the Wheal Coates tin mine in Cornwall, near the town of St. Agnes. A large pump was installed in the building to pump water out of the tin mine. The full name of the building was: Towanroath Shaft Pumping Engine House. The building was constructed in 1860 and put into operation in 1872 to keep the more than 180-meter-deep mine shaft dry. Next to the building were two other engine rooms, but these are not visible on the stamps. The buildings in the background with the two chimneys are a product of the designer's imagination. The tin mine was closed in 1889 because it was exhausted. Between 1911 and 1913, the mine was briefly put back into operation, but the yield of tin ore was so low that the mine was closed permanently. The machinery in the buildings was removed. The building is now managed by the National Trust and is therefore secured for future generations.
The National Trust took advantage of the issue by issuing its 'own' envelope. On 10 May 2007, UNESCO declared the entire industrial landscape of Cornwall and West Devon to be of very great importance for the World Heritage List.
Iron Bridge, Shropshire
The English consider Ironbridge the birthplace of the Industrial Revolution. The bridge was built to replace the ferry service across the River Severn. The need for a bridge became increasingly urgent due to the growing industrialization in the area. The idea to build an iron bridge came from Thomas Farnolls Pritchard, an architect. He designed the iron bridge in 1775 to span the valley and the river. Abraham Darby III, from Coalbrookdale, was commissioned to manufacture the components for the cast-iron bridge. In total, Darby used 379 tonnes of iron for more than 800 parts. The bridge was opened on New Year's Day in 1781. The bridge was closed to vehicles in 1934 and is now accessible only to pedestrians. The designer drew the two small arches as the same size on the block, but that is incorrect. The village of Ironbridge in the background is depicted correctly. The bridge and the village are included on the UNESCO World Heritage List.
An official first-day envelope was issued by Royal Mail for the series. This envelope, affixed with the series, was stamped on July 4, 1989, with an image of the bridge. Confusingly, Telford was also an architect and designed bridges, such as the Menai Suspension Bridge, a large suspension bridge between North Wales and the island of Anglesey, but he has nothing to do with the Iron Bridge! In this case, Telford is the name of the administrative area in which the village is located, and Salop is the old name for Shropshire.
Cotton weaving mill New Larnak, Strathclyde, Scotland
The first water-powered machines in a factory were established in 1771 by Sir Richard Arkwright in Cromford near Matlock in Derbyshire. In collaboration with Arkwright, David Dale built a new factory near Larnak in 1795, modeled after the factory in Cromford. Dale's son-in-law, Robert Owen, expanded the factory and also had social facilities constructed for his workers, including a nursery school in 1816. Owen is considered the founder of British socialism. In 1817, he advocated for the introduction of the eight-hour workday and the establishment of cooperative villages. Many workers in his factories lived on the factory grounds in houses built there, owned by the factory. The factory in New Larnak is on the UNESCO World Heritage List.
Pontcysyllte Aquaduct, Clwyd, Wales
The name of this aqueduct in the Welsh language is: Traphont Ddør Pontcysyllte. The aqueduct was built along the route of the Llangollen Canal across the valley and the River Dee. It was designed by Thomas Telford and William Jessop, completed in 1805, and put into service on November 26 of that year. The aqueduct has a length of 307 meters, a width of 3,4 meters, and a depth of 1,6 meters. In principle, it is only suitable for so-called 'narrow boats', which were formerly used as cargo vessels but are now mostly used by tourists spending their holidays on board. The aqueduct is a long cast-iron trough placed on 19 pillars. The highest point is 38 meters above the river, making it the highest and longest aqueduct in Great Britain. One can walk along a towpath next to the water trough. A railing is installed on that side, but not on the other. The aqueduct was placed on the UNESCO World Heritage List in 2009. To conclude this article, an image of the block.
The total face value of the stamps in the block amounted to £1.13. The selling price was £1.40. The difference of 27p was intended for the organization of the International Philatelic Exhibition Stamp World London 90, to commemorate the fact that 150 years earlier the world's first two postage stamps had been issued. The exhibition took place from 1 to 13 May 1990 at Alexandra Palace in London. 1.141.300 copies of the block were sold.
The official stamps for the first day of issue show only two appropriate images: the Visitor Centre in New Larnak and the Iron Bridge in Ironbridge.
But why two different first day dates, July 4 and July 25, 1989? This latter date applied to the block, as the National Trust stamp also shows.

Beautiful stamps of Industrial Heritage that they are proud of and careful with in the UK. The images continue onto the tabs and the edges of the sheet. Who is starting to complain???
Now that is PHILATELY of the highest caliber: visiting the depicted structures based on your stamp collection. Hats off to Cees!