The new INVINCIBLE range High Traffic Access Covers and Frames from TD Foundry are now IN STOCK! In both 600 x 600 and 675 x 675 sizes.
The cost of replacing damaged products has always been both a financial and logistical nightmare, having to close roads due to failing, inferior quality products and the problem is only getting worse with increased road usage and high numbers of poor quality, imported castings available in the market.
Our INVINCIBLE products have been designed to stand the test of time in very high traffic conditions and with the requirements of Highways England’s technical regulation, CD534, at the forefront of our specification.
We’re confident that the quality and design of our INVINCIBLE products means no more escalating costs and chaos of road closures, just Fit and Forget!
The CD534 regulation was introduced back in February 2020, as a replacement for the HA104/09 guidance notes, with the intention of guiding installers to the best possible product specifications for installation in trunk roads and motorways.
The TD Foundry INVINCIBLE range has been designed to conform to and in many instances exceed the requirements of both EN124-2 and CD534, the products are also Kitemarked to provide additional peace of mind.

Here is a list of key product features and how they perform against the requirements of CD534 –
Skid resistance value of 78 PSRV – This figure vastly exceeds the CD534 minimum requirement of all Group 4 chamber tops to have a PSRV >60.
Increased bedding area providing a bearing pressure of 2.05 N/mm² – Although CD 534does not specifically require a more stringent bearing pressure than the 7.5 N/mm² stated in EN124, this was a key requirement in its predecessor, HA104/09, which gave a maximum bearing pressure of 2.1 N/mm². We believe that the lower bearing pressure is key to dispersing stresses and thus reducing the potential damage on bedding materials, especially in high traffic installations and have ensured that our product still meets this specification.
E600 Load Class – CD534 now states that E600 covers should be used in ALL environments where the annual average daily traffic of large goods vehicles exceeds 1500 in each direction.
Clear opening of 675 x 675 – For chamber tops permitting access, CD534 requires a minimum of 600mm clear opening.
150mm Frame Depth – CD 534 states a minimum frame depth of 150mm for all motorways and all-purpose trunk roads.
80mm Depth of Insertion – This meets the CD 534 minimum depth of insertion of 80mm.
M16 Coupling Bolts – Exceeding the CD 534 requirement of 140mm² minimum cross sectional area of loose couplings.
In addition to the requirements of EN124 and CD534, we designed the following features into our High Traffic product –
Cover to frame contact area Increased by 600% – This is critical to disperse stresses transferred from cover through the frame and into the bedding material.
Increased strength – Greater strength allowing the product to surpass the load test requirements of both EN124-2 and the Kitemark to give greater peace of mind in high traffic locations.
Limited movement of the cover in the frame – Design features limiting the movement of the cover in situ prevent wear and potential instability of the cover.
Frame Keying Ribs – Provide greater mortar engagement with the frame than a flat surface.
All these features add up to a product that you can install with confidence, even in the busiest locations.