Advancing Ship Battle Damage Response by Integrating Distributed and Hull Systems Models

CDR Joseph Famme (ret.), ITE; Dr. C.M. Lee Ph.D., Super Century Co., Ltd.; Mr. Noel Angeles, ITE Consultant; Mr. Tobin McNatt, DRS; Mr. Ted Raitch, ITE, CDR Mike Rimmer, RN (ret.) Redhorse

Abstract FinalRick

Mission altering hull damage experienced by Stark, Roberts, Tarawa, Princeton, Cole reminds us that the Navy Policy of Distributed Lethality requires ships to fight and ‘fight-while-hurt.’ Fighting while hurt in the context of Navy Policy of Total Ship Survivability requires immediate and continuous real time readiness assessment and restoration of both distributed and hull systems to maximize available remaining combat systems sensing and firepower. Today’s HM&E distributedsystems that are designed and implemented with physics reference models are able to describe the damage to the systems. When mission altering hull damage occurstoday’s ships have few sensors capable of automatically detecting and describing structure hull damage.Describing longitudinal hull girder structure loss is the primary factor required in the Navy provided shipboard Hull Structural Strength System (HSSS) / Intelligent Decision-aids (IDA) software. Reviewed are hull sensors tested aboard the ONR X-Craft and HSV-2 to monitor stress and hull fatigue. Required are hull structure failure sensors sufficiently accurate to automatically input the damage into the NSWC HSSS-IDA decision-aids. Applications of Finite Element Analysis and Virtual Reality techniques developed for ROKN post-damage analysis of Cheonan sinkingin 2010 point to future hull damage analysis capabilities. (194)

Introduction

This paper describes options for improving automation of hull sensing and assessment, with the goal of keeping the ship afloat and in the fight to the maximum extent possible: Distributed Lethality works only with ships afloat. This paper describes a requirement to advance Ship Battle Damage Response by Integrating Distributed and Hull Systems Models. This paper expands the thesis of the paper these authors presented at the ASNE Intelligent Ship Symposium, Philadelphia, in May 2015[1]. The ASNE May 2015 paper reviewed 20 years of developing Intelligent Physics Reference Models (IPRM) to improve ship readiness, respond to battle damage and reduce total ownership costs. The physics reference models for ship design and validation and for operation of distributed systems is mature and awaits only new ship programs to fulfill the objectives. The ASNE ISS paper 2015 ended with a discussion of the need to further improve the integration of physics modeling in response to hull damage. While the application of IPRM based distributed systems for Integrated Machinery Control Systems (IMCS) and Battle Damage Control Systems (BDCS) for control and display is mature, integrating hull damage in battle currently begins with the crew entering the damaged area to identify the damaged ‘hullstructure’ and then relaying that information to the damage control station that has the Navy software for calculating the degree of damage / threat to seakeeping, or even staying afloat.

As in the ASNE ISS 2015 paper cited, the references include USNavy ships damaged in the 1980s Gulf Wars period and the recovery, and damage analysis of the Republic of Korea Frigate Cheonan in 2010, to provide insight into naval battle damage control responses. Though the Cheonan torpedo was catastrophic and beyond the ability of any ship smaller than a very large hull to survive, the forensic analysis proved the case of the North Korean guilt and developed new damage control analysis tools and decision-aids discussed in this paper.

Discussion of these topics also respond to the concerns of naval engineers describing a ‘need for a multidisciplinary approach for modeling warships in the ocean battlespace; development of a suite of physics-based software in the framework of an integrated structural design environment for timely prediction of ship structure response to the ocean battlespace; and appropriate prediction tools to assess damaged ships.’[2]

Table 1: A History of Damage in Littoral Waters

Modest at-sea / in-port Damage / Severe Damage / “Extreme Damage”
SBIR Phase II Test Criteria
Damage / fire is contained with Minimum Threat to life, ship or mission / Partially contained damage with a Moderate Threat to life / ship with rapid and correct response. Temporary loss of mobility / Potential lives lost / ship lost / total or major loss of combat capability – progressive flooding / fire spread, potential secondary explosions, mobility lost full or partial
Ship Cases Selected:
None / Ship Cases Selected:
PRINCETON[3]
TRIPOLI[4]* / Ship Cases Selected;
COLE[5]*
STARK[6]*
ROBERTS[7]*
*A common casualty of the five Case Studies given initial review was loss of either or both external and internal communications in the ships starred* in the critical time period of first response to the damage and in four cases for the duration of the damage response.
  1. STARK-FFG-31-May 1987 (Hit by 2 Exocet missiles) lost all external communications for the duration – used radios from the aircrew survival vests (PRC-90?) to communicate in the clear on air control frequency 243 MHz to notify chain of command / “world”.
  2. ROBERTS FFG-58-April 1988 (A contact mine port quarter) lost all communications initially until air lines restored to emergency diesel generators. ROBERTS was able to launch its helicopter to transfer injured.
  3. PRINCETON-CG59-Feb 1991, Manta mine in 16 meters of water. A sympathetic actuation of another mine about 350 yards from USS PRINCETON occurred about three seconds later These mine blasts caused substantial damage to USS PRINCETON, including a cracked superstructure, severe deck buckling, and a damaged propeller shaft and rudder.
  4. TRIPOLI-LPH-Feb 1991 Contact mine starboard bow) lost all external radio communications initially, used flashing light to notify ships nearby and unsecure commercial bridge-to-bridge LOS radios (Channel 16 …) plus a PRC-90 radio from an aircrew survival vest to talk on a clear 243 MHz emergency channel, action report that recommended secure military transceivers be made available.
  5. COLE-DDG67-Oct 2000 (Small boat detonation port side) lost all external communications for the duration. Because ship was in-port, CO was able to use unsecure personal cell phone to notify chain of command and “world.” Flooded both engine rooms, lost all power, internal and external communications.[8]

The Imperative to Fight-while-hurt

Surface ships can fight only if they remain afloat. Studies of US Navy Sea battles in WWII describes the ability of 1940s era Navy ships to fight after multiple hits from projectiles, bombs and Kamikaze suicide aircraft. Ship hulls and superstructures were steel and ships had large crew numbers for nearly instant response, the use of many self-defense guns of varying caliber, high degrees of compartmentation, redundant weapons, machinery systems and means of control (remote, local power, local manual). Future ships must be equally tough and resilient. Some adversaries today are capable of using swarm surface and air threats in addition to submarines. As demonstrated in the Gulf Wars period, the enemy in the littorals can also use mines effectively. Some adversary navies have announced very high speed, long range torpedoes, as well as hyper-sonic anti-ship ballistic and cruise missiles.

Navy Response to Gulf War Damage Experience

In response to the Gulf War damage 1987 the Navy has developed new decision aids to improve ship survivability. The concept of ‘Total Ship Survivability’ was developed as described in an ASNE Technical Paper published & presented in 1996[9] that discusses the development of OPNAV Instruction 9070.1 series, initiated 23 September 1988. This policy requires that all ship designs account for Susceptibility, Vulnerability and Recoverability, and for the Navy to establish minimum levels of ship survivability.

AU.S. Naval Institute February 2016 commentary on the necessity to create and adhere to ship survivability standards is, “One blindingly obvious lesson from real-world combat events is that surface ships built to military standards are more likely to survive attacks than are vessels designed to commercial standards. Indeed, numerous critical factors in the Navy’s Survivability Instruction 9070.1A are taken into account in designing U.S. Navy surface ships to three survivability standards: Level 1 (low); Level 2 (moderate); and Level 3 (high). Aircraft carriers, cruisers and destroyers are designed to Level 3. Amphibious warships and some underway replenishment ships are designed to Level 2. Both versions of the littoral combat ship (LCS), other replenishment ships, mine warfare ships, patrol craft, and support ships are designed to Level 1. Then there are Navy vessels that are built to commercial standards.”[10]

In response to the LCS class being designed to Level 1 survivability standards, one of this paper’s authors co-authored and presented a paper at ASNE Day, 2013, “Capstone Strategy to Mission Ready Ships,” reflecting concern that the LCS class design was not fully vetted for its mission.[11] This concern was also raised by others. Andrew Krepinevich, writing about the A2/AD challenges wrote, “Proponents of the LCS would counter that their smaller crew and lower costs make these risks acceptable. However, this assertion rests on a key, unproven assertion: that the loss of several small $400 million crewed combatants with 75-person crews in surprise first salvos would be more politically and operationally palatable than the loss of a $1 billion crewed combatant with a 350-person crew.”[12]The Streetfighter ship concept was conceived by Admiral Cebrowski and Wayne Hughes at the Naval War College as littoral fighting craft. As of mid-2001 the Office of Naval Research was considering construction of a Littoral Combat Ship with a displacement of 500 to 600 tons. The LCS would have a draft of about three meters, an operational range of 4,000 nautical miles, and a maximum speed of 50-60 knots. The cost per ship might be at least $90 million.”[13] LCS in 2016 is a 3,400 ton ship and is being reclassified as a frigate that would be placed, today, in the Level 2 or 3 category of survivability.

Summing up to this point, two points have been described:

  1. Hull structural strength is measurable and the key to the command decision to continue to ‘fight-while-hurt.’
  2. There are by Navy policy three levels of hulls strength / vulnerability / survivability, based on the missions Category / Class of the ships.

Regardless of Category / Class of ship, every naval ship requires appropriate networks, sensors and decision aids for both distributed and hull systems in support of a command decision to stay in the fight or abandon ship. This paper summarizes the development of distributed systems capable of self-reporting their ‘health’ status with the goal of advancing hull systems sensing technologies to assess and report the ‘health’ of the hull.

Evolution of Battle Damage Control Systems

In the 1986-92 period the U.S. Navy also began investigating two new ‘control systems’ technologies to improve the survivability of ships. One was the concept of Battle Damage Control Systems (BDCS) to augment or replace damage control grease pencil plots, with a PC computer in every Repair Locker that provided side view and a zoom-in Isometric presentation of the ship’s hull with the ability to overlay all HM&E systems: compartmentation, location of DC equipment, firemain, etc., with the ability to plot the damage electronically for all repair lockers to view the same DC picture. [The 1996 graphic shown was converted to B&W for contrast] This first generation distributed microprocessor damage control capability was demonstrated aboard USS ANZIO CG68 in 1992 with a prototype DC PC installed on a newly installed LAN in seven Repair Lockers. This system supplemented / replaced grease pencil plots and Sound Powered Phones; BDCS survived flawlessly during the USS ANZIO EMP tests held several months after installation.

BDCS revolutionized the accuracy and timely damage control communications and control: Every Repair Locker on the ship was looking at exactly the same electronically ‘plotted’ casualty status with independent ability to alter their view, and add or subtract information as new information was obtained. In 1996, this capability was installed in the US Navy Smartship, USS Yorktown CG48, in the form of the OPNAV sponsored and NAVSEA developed Navy Standard Monitoring and Control System (SMCS), that combined the first USN use BDCS DC displays installed in all Repair Lockers, as well as in CIC and on the Bridge. All consoles on Smartship could operate and display both damage control and machinery control systems, with proper logon authority from ten locations on the ship. Distributed processing with the replication of vital signals at all RTUs with backup battery power, ensured there were no single points of failure.

Advancing Integrated Machinery Control Systems

As described above, the US Navy began investigating distributed microprocessor for integrated machinery control systems (IMCS) for the same reason as described for BDCS. The first IMCS systems were installed in the RCN Tribal Class DDH and City Class Frigates, followed by the Canadian system being selected for the USN Osprey Class MCH ships as well as the Israeli SA’AR-5 corvettes built at Ingalls in the 1990s. The IMCS architecture is distributed microprocessor display consoles and triple-bus distributed remote terminal units (RTUs)architectureto eliminate the possibility of single points of control systems failure. The U.S. Navy prototype IMCS/BDCS system, the Standard Monitoring and Control System (SMCS), was built designed DDG51 Class in 1992-1996, and hot plant tested at NSWC, Philadelphia in 1996.

This architecture reduced costs and supported smaller crews as demonstrated when SMCS was installed in the Navy’s Smart Ship, USS Yorktown CG48 in 1996. Distributed SMCS processing and displays, with ten Remote Terminal Units (RTUs) with UPS protection and a triple data bus, demonstrated improved ship survivability by eliminating single points of control system failure.

Introduction of Intelligent Physics Reference Model Based Control Systems

The distinguishing feature of the BDCS-IMCS architecture was that for the first time the damage and machinery control systems architectures were developed using physics-based modeling of the distributed systems themselves: the control algorithms and the fluid, gas and electrical systems being controlled. Modeling of these processes ‘validated’ the systems as they are built, and provided on completion an Intelligent Physics-based Reference Model (IPRM) of the ships distributed systems being controlled. Thus when the ship received battle damage the SMCS/BDCS systems‘knew’ what the correct signals values should be for the ordered condition and reported post-damage values, with alarms ‘to tell’ the crew what was damaged and where to respond.

When the ship is operating normally, the same SMCS/BDCS model supports a real time On-board Trainer (OBT)for operator and team training. The benefit is that crew training moves from being ‘scenario’ (Verbal ‘what if’ training) to a dynamic real time simulation of the HM&E system and the controls. In OBT mode the scenario is initiated by a macro command to alter the running physics model, such as a ‘break or bend in a pipe or wire, thus changing the pipe flow or wire amperage … or, create a hole in a tank or hull and flood from the sea or an adjacent compartment, and is sensed by the control system as a ‘casualty’ and crew must use their Casualty Control Operation Sequence System (CSOSS, EOSS, EOCC) procedures to restore the system. The crew training is real time on the operational ship’s consoles placed in ‘Training Mode.”

Advancing Ship Design and Damage Survivability Using Intelligent Physics Reference Models for System Health Monitoring, Machinery Control and Casualty / Battle Decision-aids.

Starting with LPD17 the Navy began modeling all vital systems in 3D CAD with the Process and Instrumentation Drawings (P&IDs) of the HM&E equipment included in each ship compartment.[14] The LPD17 program added the requirement for dynamic, real time physics verification and validation (V&V) of vital system P&IDs before release of drawings to production. The HM&E systems not only needed to FIT into the ship, they also must be stress tested to WORK with all other systems, through all likely operational and battle damage scenarios over the life of the ship, from the warmest seas of the Persian Gulf, to the coldest reaches of the Arctic. Further, the HM&E systems must support the initial combat systems, with space, weight and HM&E reserves for new capabilities as they emerge, especially in the new era of flexible / modular ship designs.

There are two principal sources of ship physics models for analysis and design of control systems:

  • The as-designed CAD/physics models that were created during V&V of the designed P&IDs for the ship prior to the release of drawings to production.
  • Physics models that a ship program office creates to train the crew and maintain the ship after the ship is delivered. Virtual reality training is based on 3D CAD with physics modeling of the process, and used for the LCS program significantly.

The LPD17 was the first ‘ship’ design that required integrated CAD-Physics design that would support real time V&V of all vital HM&E / DC systems prior to the release of the drawings to production.