8 Bishopsgate, London
8 Bishopsgate
Client: Keltbray (Demolition Contractor)
Main contractor: Lendlease
Developer: Stanhope
Architect: Wilkinson Eyre
Structural engineer: Arup
Project: 8 Bishopsgate - 50-storey commercial tower
Location: City of London (corner of Bishopsgate and Leadenhall Street)
8 Bishopsgate is a 50-storey, 204-metre commercial tower delivering 52,900 m² of office space in the City of London. The building uses a hybrid stability system with two reinforced concrete cores: a full-height slender north perimeter core and a secondary east core forming a braced box between them.
We provided construction engineering from demolition of the existing Deutsche Bank building through to the basement substructure and core construction. We designed temporary works enabling the slender cores to climb ahead of the steel frame while managing stability constraints in temporary conditions.
We provided construction engineering from demolition of the existing Deutsche Bank building through to the basement substructure and core construction. We designed temporary works enabling the slender cores to climb ahead of the steel frame while managing stability constraints in temporary conditions.
50
storey, 204m commercial tower with elevated terraces
20
storey separation limit between cores and steel frame determined
52,900
m2 of commercial office space with public viewing gallery at the top
Our Role
Our RoleOur scope included structural assessment of the slender cores under varying steel frame connections, tower crane and hoist temporary works for climbing operations, embedded plate coordination with complex 3D reinforcement details, and construction sequencing to optimise the relationship between core construction and the following steel frame.
We developed finite element analysis of the cores in temporary states, designed climbing beam systems with strict movement limits, and created a hoist re-support strategy enabling early release of lift shaft zones ahead of the conventional programme.
We developed finite element analysis of the cores in temporary states, designed climbing beam systems with strict movement limits, and created a hoist re-support strategy enabling early release of lift shaft zones ahead of the conventional programme.
Capabilities
Capabilities- Buildings, Substructure
- Demolition
- Structural Engineering
- Construction Method Engineering
- Temporary Works
- Geotechnical Engineering
Proving core stability for slender profile
Proving core stability for slender profileThe north perimeter core is very slender in the north-south direction, making temporary conditions before steel frame connection critical for stability. The hybrid system allowed the upper core above level 26 to be slimmed by 20%, but this created demanding force paths during erection. The original constraint was ensuring cores reached sufficient height before steel frame construction, but as jumpform cycle times improved and steel frame cycles extended, the real challenge became determining the maximum safe separation between the completed cores and the connecting steelwork.
We conducted detailed finite element analysis of the cores, examining temporary stability with varying steel frame conditions. This analysis, linked to basic wind studies, determined safe climbing levels for the cores relative to the steel frame progress. We specified additional reinforcement in the core walls beyond permanent works requirements, enabling the cores to progress at their own pace without delays waiting for steel frame connections. Our analysis showed that the cores could safely separate by roughly 20 storeys ahead of the connected steel frame.
This independent assessment gave Lendlease certainty to maintain the high core construction momentum, with jumpform operations proceeding without artificial programme constraints tied to steel frame progress.
We conducted detailed finite element analysis of the cores, examining temporary stability with varying steel frame conditions. This analysis, linked to basic wind studies, determined safe climbing levels for the cores relative to the steel frame progress. We specified additional reinforcement in the core walls beyond permanent works requirements, enabling the cores to progress at their own pace without delays waiting for steel frame connections. Our analysis showed that the cores could safely separate by roughly 20 storeys ahead of the connected steel frame.
This independent assessment gave Lendlease certainty to maintain the high core construction momentum, with jumpform operations proceeding without artificial programme constraints tied to steel frame progress.
Designing tower crane support on climbing cores
Designing tower crane support on climbing coresTower cranes climbing the cores faced strict jumpform movement limits. Traditional climbing beam solutions would have introduced excessive loads at the top of the cores, compromising both jumpform operations and core stability during critical temporary states.
Wentworth developed climbing beam, pocket and restraint beam systems that minimised loads at the top of the cores while accommodating jumpform movement restrictions. Through detailed finite element work on the cores in temporary condition, we optimised the support locations and load paths to allow safe crane climbing without disrupting the jumpform cycle. The solution required minimal changes to the permanent works, with embedded plate details carefully coordinated through staged 3D models examining both temporary stability and final connections.
This crane support strategy enabled continuous vertical construction without delays for crane repositioning, maintaining construction momentum for both core and frame operations.
Wentworth developed climbing beam, pocket and restraint beam systems that minimised loads at the top of the cores while accommodating jumpform movement restrictions. Through detailed finite element work on the cores in temporary condition, we optimised the support locations and load paths to allow safe crane climbing without disrupting the jumpform cycle. The solution required minimal changes to the permanent works, with embedded plate details carefully coordinated through staged 3D models examining both temporary stability and final connections.
This crane support strategy enabled continuous vertical construction without delays for crane repositioning, maintaining construction momentum for both core and frame operations.
Early lift shaft works through hoist tower design
Early lift shaft works through hoist tower designTraditional hoist towers occupied lift shafts throughout construction, blocking permanent works and MEP installation until late programme, creating completion pressure.
To address this, Wentworth designed a hoist tower re-support system that allowed the hoist mast to be anchored high above foundation level. This enabled the removal of the lower mast sections early in the programme, releasing the lift shaft zone for permanent works, while the hoist remained operational for upper floor construction.
This engineering solution required detailed analysis of re-support loads, connection details with the climbing cores, and coordination with the overall temporary works strategy.
To address this, Wentworth designed a hoist tower re-support system that allowed the hoist mast to be anchored high above foundation level. This enabled the removal of the lower mast sections early in the programme, releasing the lift shaft zone for permanent works, while the hoist remained operational for upper floor construction.
This engineering solution required detailed analysis of re-support loads, connection details with the climbing cores, and coordination with the overall temporary works strategy.
Outcomes
OutcomesThrough Wentworth’s early-stage involvement providing construction engineering services, we were able to optimise the complex temporary stability design governing the construction sequence and driving the scheme’s buildability.
Key results:
Key results:
- Construction sequencing: Detailed finite element analysis of cores in temporary states gave Lendlease certainty to maintain jumpform momentum without artificial programme constraints
- Programme flexibility: Core stability assessment determined 20-storey separation limit between cores and steel frame, optimising construction sequence as actual cycle times emerged
- Crane operations: Novel climbing beam solution minimised loads at core tops while accommodating jumpform movement restrictions, enabling continuous vertical construction
- Early release strategy: Hoist tower re-support design released lift shaft zones ahead of programme, reducing finishing trade pressure at project completion
- Coordination success: Staged 3D models for embedded plate details resolved complex reinforcement interfaces between temporary support systems and permanent steel connections
- Minimal permanent works changes:Tower crane and hoist solutions achieved construction requirements with minimal modifications to Arup's permanent structure design
8 Bishopsgate achieved BREEAM Outstanding certification and is currently the tallest commercial building in the UK to reach this sustainability standard. Wentworth's construction engineering knowledge supported predictable delivery across demolition, substructure and core construction phases.