Industry Perspective
Label Application as a Factor in System Reliability
Observations on the physical role of cable identification in industrial assemblies, prompted by findings from a recent transportation safety investigation.
In November 2025, the US National Transportation Safety Board (NTSB) published findings from its investigation into the collision between the containership Dali and the Francis Scott Key Bridge in Baltimore. The incident, which occurred in March 2024, resulted in the deaths of six construction workers and the collapse of a major piece of infrastructure.
The investigation identified multiple contributing factors. Among these, the NTSB noted that wire-label banding had prevented a signal wire from being fully inserted into a terminal block spring-clamp gate, contributing to an inadequate electrical connection. This connection failure initiated a sequence of events that led to the vessel losing propulsion and steering (NTSB, 2025).
The purpose of this article is not to draw direct conclusions about industrial cable labelling from a complex maritime incident involving numerous contributing factors. It is, rather, to observe that the investigation highlights a consideration that may be relevant to those responsible for cable identification: labels are physical objects that interact with the systems they identify, not merely documentation applied after the fact.
1. Context
The physical nature of cable labels
Cable labelling is typically discussed in terms of its documentation function. Industry guidance and standards appropriately focus on factors such as legibility, durability, traceability, and consistency of identification. These priorities support the safe maintenance, modification, and operation of cable systems over their service life.
What the NTSB finding draws attention to is a separate consideration: labels, regardless of format, possess physical properties. They have thickness, stiffness, and occupy space within an assembly. When applied to a wire or cable, a label becomes part of that assembly. In configurations where clearances are limited or where connections rely on precise insertion depths, the physical presence of a label may have implications beyond its identification function.
The circumstances described in the NTSB investigation involved a specific combination of factors: the label type and its placement, the terminal block design, and environmental conditions over a service period of approximately ten years. The degree to which these findings apply to other contexts will depend on variables specific to each application.
2. Observations
Factors that may warrant consideration
For those responsible for specifying or applying cable identification in industrial environments, the following observations may be relevant. These are offered as points for consideration rather than prescriptive guidance; appropriate practice will be determined by the specific requirements, standards, and risk assessments applicable to each installation.
Label format selection
Different label formats interact differently with cables and terminations. Tie-on labels, wrap-around labels, heat-shrink markers, and other formats each possess characteristics that may be more or less suited to particular applications. The selection process may benefit from considering not only durability and legibility requirements, but also how the chosen format will physically interact with adjacent components throughout the expected service life.
Placement specifications
The position of labels relative to terminations, connectors, or other components may affect the assembly. Where this is a concern, placement specifications expressed in measurable terms may help ensure consistency across installations and between personnel.
Application consistency
Even with appropriate label selection and placement specifications, variation in application practice may occur between technicians or over time. Where consistency is important to the integrity of the installation, documented procedures and verification steps may be warranted.
3. Applicability
Contexts where these considerations may be relevant
The NTSB investigation concerned a marine vessel operating under specific conditions. Similar considerations regarding the physical interaction between labels and assemblies may be relevant in other environments, particularly those where cable terminations are densely arranged, where vibration or movement is present over extended periods, or where long service life without intervention is expected.
Such environments may include control systems with compact terminal arrangements, transport infrastructure subject to regulatory requirements, and industrial plant operating over extended periods. In each context, the appropriate approach to cable labelling will be determined by the specific requirements and standards applicable to the installation.
The general observation that labels possess physical as well as informational characteristics may be one factor among many that informs specification and installation practice. It does not, of itself, indicate that current practice is inadequate or that particular measures are required.
4. Conclusion
A measured perspective
The NTSB investigation into the Dali incident identified numerous contributing factors, of which wire-label placement was one. The full report provides a detailed account of a complex event involving vessel systems, crew response, bridge vulnerability, and emergency communication protocols. Those seeking a complete understanding of the findings should consult the primary source documents.
For professionals involved in cable identification, the investigation may serve as an occasion to consider whether application practice receives appropriate attention alongside material selection and print quality. The extent to which this consideration is relevant will vary according to the nature of each installation and the requirements applicable to it.
This article has sought to present the matter in measured terms, recognising both that the NTSB finding is noteworthy and that its direct applicability to other contexts should not be overstated.
Further Information
Silver Fox® labelling products
Product Information
Silver Fox® manufactures a range of cable and equipment labelling products for industrial applications. For product information, technical specifications, or to discuss requirements for a particular application, please contact our team.
Email: sales@silverfox.co.uk | Telephone: +44 (0) 1707 37 22 22
References
NTSB (2025) Loose Wire on Containership Dali Leads to Blackouts and Contact with Baltimore's Francis Scott Key Bridge. Press release, 18 November 2025. Available at: https://www.ntsb.gov/news/press-releases/Pages/NR20251118.aspx
NTSB (2025) Contact of Containership Dali with Francis Scott Key Bridge: Final Report. Washington: National Transportation Safety Board, December 2025.
