Cleaner for the Time Domain Reflectometer Tank Level Indicator

Fouling on the TDR sensor used for TLI is a persistent problem. The TDR is necessary to provide accurate and precise readings for fuel measurement. Over time, TDRs can experience sensor fouling through a buildup of crystallization and other contaminants on TDR rods and tubes, contributing to false readings or other failures if not properly maintained and cleaned.

The operational readiness of the U.S. Navy's DDG 51 Arleigh Burke-class destroyers is being undermined by a persistent and unsolved equipment failure. The TDR sensors, a TLI technique, which are critical for managing fuel, buoyancy, and stability, are consistently rendered unreliable due to fouling. Current cleaning methods are operationally untenable; they require taking fuel compensating tanks offline, emptying fuel and/or compensating seawater, and significant follow-on maintenance, which directly reduces the Fleet's readiness and deployability. These efforts are not a permanent solution and often fail to resolve the underlying issue, making this a high-priority challenge for the DDG 51 Program Office.

The Navy urgently seeks an innovative solution that remedies fouled TDR units without requiring ships to cease operations or undergo costly, invasive maintenance, thereby increasing mission readiness and reducing the risk of fuel spills.

Effective methods for cleaning these sensors in-situ are very limited. The existing approach involves decompensation of fuel tanks (removal of fuel and compensating seawater) and manual removal of TDR sensors for cleaning, which can be costly and time consuming. It is not generally feasible while the ship is underway. Removal of TDR sensors during these manpower-intensive efforts can sometimes lead to TDR sensor miscalibration during re-installation.

The inability to effectively clean TDR sensor fouling is a critical point of failure. The buildup of crystallization and other contaminants on TDR rods and tubes creates false readings and electrical shorts, leading to inaccurate fuel measurement and extensive tracking errors. This directly compromises the precise fuel management necessary for the ship's stability and mission readiness. Current ships have had fuel spills due to TDR TLI fouling. Additionally, scheduled maintenance periods to remove and clean fouled TDR TLI units inherently cause time delays and ship-wide disruptions affecting other planned work. .

The Navy seeks a product that cleans and potentially reverses the fouling buildup throughout the entire TDR assembly while being compatible with the existing sensor architecture. The technology must return the installed TDR and TLI technique to full operational status upon one execution of the developed technology/technique over an objective period of 36 months, but not less than a threshold period of 8 months of full TDR TLI operability. This effort is required to develop a comprehensive technique that resolves this persistent reliability challenge. A more precise fuel management and reduction in potential failures will result in greater ship stability and increased mission readiness.

Objective

Develop a technology to clean and potentially reverse fouling on Time Domain Reflectometer (TDR) Tank Level Indicating (TLI) components in-place. The solution must function within fully compensated fuel tanks aboard DDG 51 class ships without requiring depressurization, defueling, or dewatering.

Phase I

Develop a concept for a product/technology to clean a fouled TDR TLI in-situ, returning it to full operational status within the challenging environment of a compensated fuel tank. Detail how the cleaning technology would be employed on an in-service ship while underway. Establish feasibility through small-scale testing, analysis, or modeling. If the Phase I Option is exercised, include the initial design specifications and capabilities description to build a prototype solution in a Phase II plan.

Phase II

Develop, deliver, and demonstrate a prototype of the anti-fouling solution that meets the requirements in the Description. Prove in a demonstration that the technology can return a fouled TDR TLI to full operability in a simulated confined space without requiring the tank to be emptied or causing fuel spills. Design the solution to minimize or eliminate the need for personnel to access the tank, a key limitation of current procedures. Identify all necessary Navy testing for shipboard certification. Prepare a Phase III commercialization/transition plan.

Phase III

Support the Navy in transitioning the cleaning technology for Fleet-wide use, providing the necessary equipment, training, and logistical documentation.

A successful solution to this problem on the DDG 51 class is expected to be highly applicable to other ships facing similar challenges with compensated fuel tanks and TDR TLIs, including the LHD 1 and LHA 6 classes. The goal is to field a fully qualified and certified solution that resolves this long-standing maintenance and readiness issue across the surface fleet.

Commercial fuel tank farms as well as other industrial operations requiring high level of awareness of tank full status can benefit from development of this technology.

Keywords: Time Domain Reflectometry; Tank Level Indicator; Fuel Fouling; TDR rods and tubes; Compensated Fuel Tanks; Crystallization

Technology areas: None

Focus areas: Sustainment & Logistics

CMMC level: Level 2 (Self)