Double beam engine

Double beam engine

Double beam engine

​In 2021 it will 50 years since Blists Hill Victorian Town Museum opened to the public. In keeping with the areas innovative past, the Blists Hill museum was a first for a new type of open air museum. We were thrilled to be invited by The Ironbridge Gorge Museum to undertake an inspection of the double beam engine and structure at the Blist’s Hill Victorian Museum to determine if the exhibit could be reopened for close viewing by the public or brought back into use as a part of the 50 year celebrations.

The double beam engine was built by Murdock Aitken and Company of Glasgow in 1851 for use by the Lilleshall Company to increase production at it’s Priorslee works. The works were situated in what is now the Hollinswood Road area of Telford. The beam engine was so successful that the Lilleshall Company also started fabricating the engine.

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As is typical with Victorian design and fabrication intricate details are added to the support structure such as doric columns and ornate detailing on the beams, even though this was to be in a steel works. This sort of detailing is no longer common-place in today’s engineering, with functionality and cost efficiency taking precedence over the Victorian values.

The design of the double beam engine was innovative as it used a single flywheel to power two parallel beams that provided the compressed air to the furnace. In case you haven’t been fortunate enough to see a fly wheel and beam engine in motion, a simplified example is above.

The double beam engine was in full time use until the early 1900’s and was then used as a standby engine until the works were closed in 1951.

Following the closure of the Priorslee steel works and during the development of the Blists Hill Museum the double beam engine was to be moved to be an exhibit at the new innovative open air museum.

In 1971, the antecedent of Thomas Consulting, the Telford Development Corporation were tasked with designing the new support structure for the double beam engine. Reinforced concrete pits were designed to support the flywheel and a steel structure to support the double beams where these used to bear onto masonry walls in the original location.

The scope of our inspection was to determine the works required to allow the exhibit to reopen as a static exhibit and additional works to allow the double beam engine to be put back into use thereafter.

Unfortunately, the inspection found that the base slab to the blow cylinders did not extend far enough to support the base of the blow cylinders and that supports for the flywheel were not accurately positioned to support the base plates. No moving part was installed accurately to line and level, which is paramount in this installation of this kind.

The lack of accurate positioning created eccentricities into the system that meant other areas were not correctly aligned. To enable the double beam engine to be brought into use during the 1980’s areas of steel were cut from the supporting columns and cylinders due to clashes with moving parts.

It is disheartening that a valuable piece of engineering history, that worked for almost a century in its original position, should not have been brought back into use 40 years ago due to a lack of accuracy in its installation 50 years ago. Due to these defects, damage has been sustained to the structural frame supporting the beams due to out of plane forces. To enable the double beam engine to be brought back into use significant works are required to allow the mechanical items to be installed accurately to line and level. If only as much care and pride was taken in these works 50 years ago the double beam engine could still be in use today.

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If you require an inspection, please do not hesitate to contact one of our offices. As you can see we love investigating and providing a solution.

Cracks in your property

Cracks in your property

Cracks in your property

Depending on where you live a colloquial term for “fun, entertainment and conversation” is ‘crack’. It often turns up in writing from Northern England and Scotland such as Walter Scott and Robbie Burns. I know someone will be saying it should be ‘craic’ but this gaelicised spelling that has been absorbed into everyday use gained popularity in the 1960’s following its use in an advertisement in the Irish newspaper Connacht Sentinel; “ceol agus craic”, you may have seen this outside many ‘Irish’ pubs; it means “music and fun”.​

But I have digressed, back to cracks. Whilst you may not think of cracks as being fun and entertaining, I’m going to go out on a limb here, they certainly can be interesting.

One thing that cannot be disputed is that cracks in our homes or properties are a cause of concern; structures move for a variety of reasons.

A common cause of cracking is thermal movements. Cracking due to thermal movements are often of uniform width and are vertical. However, there are occasions when the normal rules are not followed; as shown in the photograph below where the shadow from the rest of the property contributed to different thermal expansion and cracking in this masonry wall. It is now common practice to include movement joints in new masonry structures to accommodate thermal movement so cracking due to thermal movement has reduced.

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Often we see cracks over windows to doors, but as we like to call them structural openings. Historically window and door frames were installed into buildings as the masonry progressed and brick arch lintels or concrete lintels in post war housing were used over the frame to provide additional support. In these cases the window frames also supported the masonry above. It was not until recently that lintels were used over windows to fully support the masonry over and allow windows to be inserted when the masonry works were completed. This allows for easy window replacement also. The cracking we see over windows and doors usually is in older properties when windows have been replaced. Unfortunately, not all window installers in the past checked that the existing lintels were adequate and remedial works are then required.

The most worrying of all cracking is that caused by foundation movement. Whilst all buildings settle following the initial construction, properties can suffer foundation movement for a number of reasons:

  • Leaking water pipes or drains
  • Influence of trees
  • Weak ground and inadequate foundations

Stepped diagonal cracking is typical of foundation movement, the width, pattern and position of the cracks allow the engineer to determine the likely cause of cracking. Sometimes, further investigation to prove ground conditions are required. Depending upon the foundation types and the cause of failure other cracks can also appear such as horizontal or vertical cracks.

Decay of materials in properties can also lead to cracking and if left unchecked over a long period of time can lead to failure.

The level of damage in the images below was caused by decay to floor joists that the walls were built off.

If you are concerned about any cracks in your property, please do not hesitate to contact one of our offices. As you can see we love having the craic about cracks.