## 5 Case Studies
### Case Study 2: Stoke-on-Trent Station Gable End Replacement  
Another case was initiated in March 2020 in response to the deterioration of two gable ends at Stoke-on-Trent Station as shown in Figure 10, which posed a significant safety risk to passengers and train operations. Due to the structural instability, the issue was escalated to the project team, who conducted an initial cost forecast. The estimated budget was set at three million GBP, primarily based on a comparable project previously undertaken at Preston Station. However, this estimate was largely analogous, relying on similarities in scope rather than a detailed site-specific assessment. One of the significant challenges faced in this case was the discharge of Listed Building Consent (LBC). During the design development phase, it was initially assumed that an \begin{table}
\begin{tabular}{c c c} \hline \hline
**Cost to Implement 2014 Repair Design** & **Cost to Implement Design Incorporating Contemporary Material in 2024** \\ \hline Shiplap treated Redwood 150 mm \(\times\) 15 mm—134 @ & 300 mm \(\times\) 15 mm Textured 134 @ & GBP 2613 \\ GBP 16 & & @ GBP 39 \\ \hline Dulux wood primer undercoat & & \\ GBP 22.89 for 13.5 m\({}^{2}\) & GBP 183.12 & N/A \\ coverage—100 m\({}^{2}\) in total & & \\ \hline Dulux Trade & & \\ Weathershield Quick-Drying & & \\ Exterior Satin Tinted & & \\ Colours GBP 36.84 for 13.5 m\({}^{2}\) & & N/A \\ coverage 100 m\({}^{2}\) in total & & \\ \hline Fixings and Sundries & GBP 350 & Fixings and Sundries & GBP 124 \\ \hline SX Contractors Silicone \(\times\) 25 & & SX Contractors Silicone \(\times\) 25 \\ Tubes LMN—Neutral—White & GBP 68.75 & Tubes LMN—Neutral—White @ GBP 2.75 \\ \hline Installation costs—3 skilled & & \\ men \(\times\) 24 weeks & & \\ \hline Total = & GBP 115,041 & & GBP 76,806 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Cost comparison of the 2014 and 2024 designs. Figure 10: Condition of Stoke-on-Trent station gable ends before commencement of the replacement. aluminium frame would be an acceptable solution, as it had been approved in a similar project. However, discussions with the planning officer confirmed that only a like-for-like timber replacement would be permitted, and the proposal to use aluminium would be rejected. [PERSON] et al. documented similar regulatory challenges in the Ordsall Chord project [45]. The asset engineer explored various softwood alternatives, but Accoya(r) was ultimately selected to maximise design life, as shown in Figure 11. Accoya(r) is an engineered timber, for which pine trees are harvested at maturity (approximately 30 years old) and subjected to an acetylation process using acetic acid. This modification enhances the dimensional stability and durability of the wood [46]. The procurement of Accoya(r) contributed approximately one million GBP to the total project cost. Had alternative materials been accepted by the planning officer, significant cost savings could have been achieved. Additionally, the requirement for a like-for-like timber replacement resulted in a two-year delay as the design underwent an extended approval process. Beyond the material selection challenge, the project also encountered difficulties in terms of the construction methodology. The original plan proposed lifting the wooden frame in one piece through a piecemeal approach. However, this method proved to be infeasible due to site constraints, including overhead line equipment (OLE) and limited headroom, which prevented the supplier from executing this approach as a cost-saving measure. These constraints necessitated an alternative construction strategy, further complicating project execution. The challenges associated with the material change, design delays and modifications, and the constructability of a single wooden span over an operational railway have resulted in significant cost implications, as detailed in Table 3. Beyond the initial financial impact, the long-term maintenance obligations of the wooden frame must also be considered.