MIL-DTL-24640/5 TTXS, TTXSW, TTXSO, and TTXSOW Shipboard Cable

Mil-Spec Military part number MIL-DTL-24640/5 has four cable-type designations: TTXS, TTXSW, TTXSO, and TTXSOW. The cable is rated for 600 volts and uses Standard Identification Code by Method 2. 24640/5 cords use Extruded irradiated cross-linked Polyalkene insulation with irradiated cross-linked Polyvinylidene Fluoride (PVDF) insulation and have a low-smoke zero-halogen (LSZH) cross-linked polyolefin (XLPO) jacket. The cable contains multiple conductors, with twisted pairs of two component wires, one black and one white twisted together to form a pair. The two conductors are insulated as discussed above and tested in accordance with SAE-AS81044/12 except that the identification will be according to MIL-STD-24640. Each pair can then have an optional binder tape, followed by a braided shield of 38 AWG tin-coated copper braid. An additional shield insulation of two polyester tapes or a single polyester tape with an extruded jacket is added. The required number of shielded pairs are cabled together with an optional binder tape.

 

For TTXS or TTXSW, the assembly is then enclosed in a cross-linked polyolefin (XLPO) jacket. For TTXSO or TTXSOW, an additional tin-coated overall braided shield is added, and the cord is enclosed in a cross-linked polyolefin (XLPO) jacket. These cords are lightweight and have non-flexing service. TTX is non-watertight and TTXWB is watertight. Both cables operate within a temperature range of -20°C to +105°C. Watertight cables can operate in a wide variety of situations, including through bulkheads and between decks. Non-watertight cables can be used within one or two continuous compartments, but are not permitted to penetrate bulkheads or watertight decks.

What does the cable designation TTXS mean?

In the cable designation for TTX, the initial letter T refers to twisted pairs, the second T refers to two conductors per pair, X refers to irradiated cross-linked Polyalkene insulation with irradiated cross-linked Polyvinylidene Fluoride (PVDF) insulation, and S refers to individual shielding in 38 AWG copper braid shield of each pair.

What does the cable designation TTXSW mean?

In the cable designation for TTX, the initial letter T refers to twisted pairs, the second T refers to two conductors per pair, X refers to irradiated cross-linked Polyalkene insulation with irradiated cross-linked Polyvinylidene Fluoride (PVDF) insulation, S refers to individual shielding in 38 AWG copper braid shield of each pair, and W refers to the watertight nature of each cable.

What does the cable designation TTXSO mean?

In the cable designation for TTX, the initial letter T refers to twisted pairs, the second T refers to two conductors per pair, X refers to irradiated cross-linked Polyalkene insulation with irradiated cross-linked Polyvinylidene Fluoride (PVDF) insulation, S refers to individual shielding in 38 AWG copper braid shield of each pair, and O refers to the overall shielding of the cable in tin-coated copper braid shield.

What does the cable designation TTXSOW mean?

In the cable designation for TTX, the initial letter T refers to twisted pairs, the second T refers to two conductors per pair, X refers to irradiated cross-linked Polyalkene insulation with irradiated cross-linked Polyvinylidene Fluoride (PVDF) insulation, S refers to individual shielding in 38 AWG copper braid shield of each pair, O refers to the overall shielding of the cable in tin-coated copper braid shield and W refers to the watertight nature of each cable.

M24640/5 Construction:

• Conductors:
  • Non-watertight: 19-strand tin-coated copper conductors
  • Watertight: 7-strand tin-coated copper conductors
• Insulation: Extruded irradiated cross-linked Polyalkene insulation with irradiated cross-linked Polyvinylidene Fluoride (PVDF) insulation
• Shielding:
  • Each pair of conductors features an overall tin-coated copper braid shield
  • For TTXSO and TTXSOW, there is an additional overall optimized tin-coated copper braid shield
• Jacket: Low-smoke zero-halogen (LSZH) cross-linked polyolefin (XLPO).

M24640/5 Ratings and Approvals

• Mil-Spec: MIL-DTL-24640
• Navy Shipboard Spec:
  • TTXS for shielded pairs, non-watertight
  • TTXSW for shielded pairs, watertight
  • TTXSO for shielded pairs, overall braid shield, non-watertight
  • TTXSOW for shielded pairs, overall braid shield, watertight
• SAE-AS81044/12 except that the identification will be according to MIL-STD-24640
• Voltage Rating: 600V

Features and Benefits of M24640/5 Cords

• Watertight cables can operate in a wide variety of situations, including through bulkheads and between decks.
• Cross-linked polyalkene/polyvinylidene fluoride insulation provides protection in environments with ultra-high vacuum, high temperatures, and ionizing radiation.
• LSZH jacket is fire resistant and emits low smoke, which is ideal for shipboard settings which often have restricted ventilation
• LSZH jackets also emit low acid, gas, and toxicity when subjected to fire, maintaining circuit integrity
• Braided shielding is heavier than foil shielding and provides additional protection against EMI/RFI as well as protecting the cable in rugged environments. The braided shield also provides better grounding than foil shields.