D19H & D20 Test Preparation Goals and Options

More voltage tap channels (priority=1):

+----------------------+-----------------------+-----------------------+
| **Option**           | **Plus**              | **Minus**             |
+----------------------+-----------------------+-----------------------+
| 1.  No change:       | No hassle, no risk.   | Lose info on failure  |
|                      |                       | location.             |
+----------------------+-----------------------+-----------------------+
| 2.  Add wires:       | No risk to present    | More heat load,       |
|                      | system.               | difficult.            |
+----------------------+-----------------------+-----------------------+
| 3.  Replace "1.8K    | Less heat load to     | Some new technology   |
|     direct wires"    | 1.8K reservoir.       | risk.                 |
|     with bronze:     |                       |                       |
+----------------------+-----------------------+-----------------------+
| 4.  Replace all      | Min. heat-load to     | Maximum new           |
|     V-tap wires with | both reservoirs;      | technology risk.      |
|     bronze.          | Improved hook-up      |                       |
|                      | convenience.          |                       |
+----------------------+-----------------------+-----------------------+

**[Diagnostic Wiring Requirements:]{.underline}**

1.  Need more wires, but less heat-load (goal: \< 10W to 4.3K, \< 1W to
    1.8K).

2.  Helium-gas sealable @ 300K.

3.  Helium II sealable @ 1.8K.

4.  Flexible and strong enough to pull in new wires as the old wires are
    removed.

5.  Rugged enough to last many years without maintenance.

6.  Sufficient kind and \# of wires to meet future magnet requirements.

7.  Insulation (relative to ground): 1 KV (air regions); 7KV (helium
    regions).

8.  Heater wires large enough to deliver 80% of stored voltage to 3 ohms
    at 300K.

9.  Spare wires (10%).

10. Modular enough to permit partial replacement of damaged modules in
    the future.

11. Easy magnet disconnect.

12. Easy cryostat removal

Maximum Cryostat Diagnostics:

  -------------- --------------------------------- ------------------ -------------
  **Location**   **4-wire**                        **2-wire**         **Total
                                                                      Wires**

  **Vacuum**     T5/6/7, JT-Heater^2^              0                  (16)^4^

  **LL1**        T1/2/3/4, LL1^1^                  0                  (20)^4^

  **LL2**        T10/11, LL2^1^                    0                  12

  **LL3**        T22/23/24/25/26/28/29, LL3^1^,    0                  40
                 2-Heaters^2^                                         

  **LL4**        T9, LL4^1^, \[LL4S^1^\]^3^,       0                  20
                 \[GaLo\]^3^, \[GaHi\]^3^                             

  **Magnet**     T30-39 (Mag, 5 splices, 4 pole    \[2-microphone\]   44
                 gauges)                                              

  **Total**      37 x 4                            2 x 2              116+ (36)
  -------------- --------------------------------- ------------------ -------------

1)  LHe sensors require 75 mA dc.

2)  Requires 25 Wdc: 100 ohm heaters require 50 V @ 0.5A, 1K ohm heaters
    require 160 V @ 0.16A.

3)  \[xxx\] = optional back-up (can be borrowed).

4)  \(xx\) = old feed thru.

Maximum Diagnostic Wire Requirements:

+--------+----------+-----------+-----------+-----------+-----------+
| **Ma   | **V      | **C       | *         | **Heater  | **Heater  |
| gnet** | oltage** | ryostat** | *Strain** | Supply**  | Monitor** |
|        |          |           |           |           |           |
|        | **Tap**  | **        | **Gauge** |           |           |
|        |          | Monitor** |           |           |           |
+--------+----------+-----------+-----------+-----------+-----------+
| **Pre  | 47       | 128 +     | Shared    | Shared    | Shared    |
| sent** |          | (36)      |           |           |           |
|        | 26 Ga.   |           | (Cryo)    | (Vtap)    | (Vtap)    |
|        | Cu       | 26 Ga. Cu |           |           |           |
+--------+----------+-----------+-----------+-----------+-----------+
| **L    | 7        | 128 (32 x | 0         | (2x2)x4 = | 2x2 = 4   |
| BQF1** |          | 4)        |           | 16        |           |
+--------+----------+-----------+-----------+-----------+-----------+
| **L    | 69       | 128 (32 x | 22 x 4 =  | (4x2)x2 = | 4x2 = 8   |
| BQF2** |          | 4)        | 88        | 16        |           |
+--------+----------+-----------+-----------+-----------+-----------+
| *      | 72       | 152 (38 x | 16x4 = 64 | (4x2)x2 = | 2x2 = 4   |
| *D20** |          | 4)        |           | 16        |           |
|        |          |           | (8        |           |           |
|        |          |           | pole^4^ + |           |           |
|        |          |           | 8         |           |           |
|        |          |           | end-cell) |           |           |
+--------+----------+-----------+-----------+-----------+-----------+
| **Prop | 100^1^   | 192^2^ +  | Shared    | 16        | Shared    |
| osed** |          | (36)      |           |           |           |
|        | 32 Ga.   |           | (Cryo)    | 26 Ga.    | (Vtap)    |
|        | P-Cu     | 32 Ga.    |           | Cu^3^     |           |
|        |          | P-Cu      |           |           |           |
+--------+----------+-----------+-----------+-----------+-----------+

1)  10 bundles of 5 twisted-pairs/bundle, individually potted within its
    own Teflon tube.

2)  6 bundles of 16 twisted-pairs/bundle, individually potted within its
    own Teflon tube (PG3-8).

3)  4.3K intercept provided.

4)  The 8 inner pole gauges exit at the return-end and are not counted
    in this summary.

**[Magnet Diagnostic Amplifier Requirements:]{.underline}**

[Diagnostic Goals:]{.underline}

1.  Locate quench origins.

2.  Verify proper heater operation.

3.  Locate fast motions: coil, axial position, & azimuthal angle.

4.  Measure splice voltages.

+------+--------------+----------+--------+-------+--------+--------+
| **   | **Voltage**  | **Deri   | **Im   | *     | **Vhe  | **To   |
| Magn |              | vative** | bal.** | *Ihea | ater** | tals** |
| et** |              |          |        | ter** |        |        |
+------+--------------+----------+--------+-------+--------+--------+
| *    | (See below)  | 10       | 50mV   | 100A  | 500V   | n.a.   |
| *Ran |              | 0-500V/s |        |       |        |        |
| ge** |              |          |        |       |        |        |
+------+--------------+----------+--------+-------+--------+--------+
| *    | 4 coils      | 4 coils  | T-B    | Ih6,7 | Vh6,7  | 11     |
| *LBQ | (250V)       |          |        |       |        | volts. |
| F1** |              | 1        | 1-2    |       |        |        |
|      | Vmag (500V)  | seg/coil |        |       |        | 4      |
|      |              |          | 3-4    |       |        | deriv. |
|      | 2-leads      | = 4      |        |       |        |        |
|      | (2V).        |          |        |       |        | 3      |
|      |              |          |        |       |        | imbal. |
|      |              |          |        |       |        |        |
|      |              |          |        |       |        | To     |
|      |              |          |        |       |        | tal=18 |
+------+--------------+----------+--------+-------+--------+--------+
| *    | 4 coils      | 4coils   | T-B    | Ih1,  | Vh1    | 15     |
| *LBQ | (250V)       |          |        | 2,3,4 | ,2,3,4 | volts. |
| F2** |              | 17       | 1-2    |       |        |        |
|      | Vmag (500V)  | s        |        |       |        | 68     |
|      |              | egs/coil | 3-4    |       |        | deriv. |
|      | 2-leads      |          |        |       |        |        |
|      | (2V).        | \<= 68   |        |       |        | 3      |
|      |              |          |        |       |        | imbal. |
|      |              |          |        |       |        |        |
|      |              |          |        |       |        | To     |
|      |              |          |        |       |        | tal=86 |
+------+--------------+----------+--------+-------+--------+--------+
| **D  | 8 coils      | 4 coils  | T-B,   | Ih1,  | Vh1    | 19     |
| 20** | (250V)       |          | 1-2,   | 2,3,4 | ,2,3,4 | volts. |
|      |              | 15       | 3-4.   |       |        |        |
|      | Vmag (500V)  | s        |        |       |        | 60     |
|      |              | egs/coil | 1i-o,  |       |        | deriv. |
|      | 2 leads (2V) |          | 2i-o,  |       |        |        |
|      |              | = 60     |        |       |        | 20     |
|      | 8 splice     |          | 3i-o,  |       |        | imbal. |
|      | (10mmV).     |          | 4i-o.  |       |        |        |
|      |              |          |        |       |        | 8      |
|      |              |          | Q-A    |       |        | m      |
|      |              |          | (13).  |       |        | icroV. |
|      |              |          |        |       |        |        |
|      |              |          |        |       |        | Tot    |
|      |              |          |        |       |        | al=107 |
+------+--------------+----------+--------+-------+--------+--------+

**[DiagnosticWiring Implementation]{.underline}**

1.  Polyimide-insulated, 32 Ga. P-Cu, twisted-pair wires.

2.  Multiple wires within Teflon tubing (voltage isolation & sealing
    ease).

3.  Soft epoxy potted-in-tubing (warm-flexible internal helium seal).

4.  2-Way vacuum potting, with labeled/prestripped wires & extension
    tubes.

5.  3" long, greased 1.8K helium plug .

6.  Swaged-RTV 300K helium plug.

7.  Terminal strip patching, lead-ins to magnet extension-cords, 1.5"
    centers.

8.  Strain-reliefs for module ends.

9.  Mylar-sheet pin protectors under and between T-strips.

10. 7' umbilical extension cords plug into male pin connectors on the
    magnet.

11. Low-voltage warm interface: standard 32-pin Amphenol (6).

12. Low-voltage magnet interface: 100 pin Hypertronics (1).

13. High-voltage warm interface: 50 pin Hypertronics (2).

14. High-voltage magnet interface: 50 pin Hypertronics (4, skipping
    rows).

15. 4-Pin heater supply connector with patching T-strip on magnet.

16. Magnet connectors: inward-facing pins, out-facing solder terminals.

D20 Voltage-Tap and Quench-Heater Penetration-Wiring Specifications

+----------------------+---------------------------------+-------------+
| **Feature**          | **V-Monitor**                   | **Heater**  |
+----------------------+---------------------------------+-------------+
| \# of wires/bundle:  | 10                              | 4           |
+----------------------+---------------------------------+-------------+
| \# of bundles:       | 10                              | 1           |
+----------------------+---------------------------------+-------------+
| Wire size:           | #32, twisted, solid (P-Cu).     | #18 Cu      |
+----------------------+---------------------------------+-------------+
| Insulation:          | Teflon protected polyimide.     | Same        |
+----------------------+---------------------------------+-------------+
| Warm connections:    | Shielded terminal-strip array.  | Same        |
+----------------------+---------------------------------+-------------+
| Cold connections:    | Circum. terminal-strip array.   | Same        |
+----------------------+---------------------------------+-------------+
| Connector labels:    | Section ID \[Loc# from pole\]   | Section ID  |
|                      |                                 |             |
|                      | (D2C7, Q4A2, Q1B5, D1D8).       | (D2C, Q4A)  |
+----------------------+---------------------------------+-------------+
| dB/dt noise:         | Individually twisted bundles.   | Same        |
+----------------------+---------------------------------+-------------+
| Electro-static       | Shielded (cryostat to           | Same        |
| noise:               | amplifier).                     |             |
+----------------------+---------------------------------+-------------+
| 300K helium seal:    | Swaged RTV epoxied tubes.       | Same        |
+----------------------+---------------------------------+-------------+
| 1.8K helium seal:    | RTV sealed/Teflon plug.         | Same        |
+----------------------+---------------------------------+-------------+
| 300K heat-intercept: | Cold-vapor counter-flow.        | Spiral      |
+----------------------+---------------------------------+-------------+
| 4.3K heat-intercept: | 3" insul. coincident with He-II | Spiral      |
|                      | seal.                           |             |
+----------------------+---------------------------------+-------------+

**Voltage-Tap Wiring Panel Layout**

**[Features:]{.underline}**

1.  Array layout via terminal-strips (for easy re-wiring).

2.  Far-apart taps (higher voltage) are generally farther apart.

3.  Array element labels are the 1-100 as on the SHV patch-panel.

4.  Easy labeling alternative: compatible with any magnet less than (or
    equivalent to) a 2-layer quad, or a 4-layer dipole.

5.  Voltage isolation = 7KV (warm air).

6.  Cover to protect fragile wiring/pins.

**Quench-Heater Wiring Panel Layout**

**[Features:]{.underline}**

1.  Two independent power supplies

2.  Two 2-wire I-supply sets (#18-stranded, Cu).

3.  Two 8-wire V-monitor sets (#32-solid, P-Cu).

4.  Series/parallel connection capability at cold end.

5.  Easy interface to present Quench-Heater PS.

6.  Labeling scheme consistent with V-Tap scheme, permitting easy ID of
    heater location.

7.  Terminal-strip hook-up flexibility.

**Hardware Layout**

Plumbing Changes:

+-----------------------+-----------------------+----------------------+
| **Old**               | **New**               | **Reason**           |
+-----------------------+-----------------------+----------------------+
| 1.  2" Elbow to       | 2" Tee + 1"RL         | Diag. wires access.  |
|     lift-plate:       |                       |                      |
+-----------------------+-----------------------+----------------------+
| 2.  Hi-V tree:        | P-gage R-L            | Better usage.        |
+-----------------------+-----------------------+----------------------+
| 3.  10psi R-V tree    | Turned upside-down.   | No H~2~O danger.     |
|     (El+Tee+El)       |                       |                      |
|                       | Tee+El.               | Fewer joints.        |
+-----------------------+-----------------------+----------------------+
| 4.  20psi R-V tree    | Turned upside-down.   | No H~2~O danger.     |
|     (Tee+Tee+Tee)     |                       |                      |
|                       | Tee+Tee               | Fewer joints.        |
+-----------------------+-----------------------+----------------------+
| 5.  25psi lift-plate  | Shorten               | Reduce moment.       |
|     riser             |                       |                      |
+-----------------------+-----------------------+----------------------+

LHe Displacer Requirements:

+--------------------------------+-------------------------------------+
| **Requirement**                | **Implication**                     |
+--------------------------------+-------------------------------------+
| 1.  LHe displacement:          | Leak-free containers.               |
+--------------------------------+-------------------------------------+
| 2.  Substantial reduction in   | Close or nested cylinders, as long  |
|     LHe volume:                | as practical.                       |
+--------------------------------+-------------------------------------+
| 3.  Low heat-capacitance:      | Substantially empty.                |
+--------------------------------+-------------------------------------+
| 4.  No explosion danger:       | Small energy containment            |
|                                | capability.                         |
+--------------------------------+-------------------------------------+
| 5.  Competitive with LHe       | 3-4 \$/liter.                       |
|     costs:                     |                                     |
+--------------------------------+-------------------------------------+
| 6.  Rugged, durable, reusable: | Tough, abuse-tolerant skin/housing. |
+--------------------------------+-------------------------------------+
| 7.  No danger to refrigerator: | No dust generation.                 |
+--------------------------------+-------------------------------------+
| 8.  No danger to magnet        | Relatively easy insertion.          |
|     wiring:                    |                                     |
|                                | Light weight.                       |
+--------------------------------+-------------------------------------+
| 9.  Repairable:                | Resealable.                         |
+--------------------------------+-------------------------------------+
| 10. Minimal pump/purge         | Minimal virtual leaks.              |
|     contamination:             |                                     |
+--------------------------------+-------------------------------------+

LHe Displacer Solutions:

+------------+---------------+-----------------+-----------+---------+
| *          | **Sta         | **Hollow        | **Hollow  | *       |
| *Feature** | cked-Cylinder | Sphere**        | Sphere    | *Vacuum |
|            | Vacuum Logs** |                 | Insert**  | I       |
|            |               | **Filled-Logs** |           | nsert** |
+------------+---------------+-----------------+-----------+---------+
| 1.         | Hex-packed    | Welded aluminum | Two.      | Two,    |
|   Cylinder | tubing.       | skins.          |           | SS.     |
|            |               |                 | Co        |         |
|    shapes: |               |                 | ncentric. | Conc    |
|            |               |                 |           | entric. |
+------------+---------------+-----------------+-----------+---------+
| 2.         | Multiple 2"   | Rolled, thin    | Same      | Same,   |
|   Low-cost | Conduits.     | wall skin.      |           | but     |
|     skin:  |               |                 |           | t       |
|            |               |                 |           | hicker. |
+------------+---------------+-----------------+-----------+---------+
| 3.  Low    | Empty         | Predominantly   | Same      | Vacuum  |
|     heat   |               | filled with     |           |         |
|     ca     |               | hollow balls.   |           |         |
| pacitance: |               |                 |           |         |
+------------+---------------+-----------------+-----------+---------+
| 4          | Metal tubes.  | Vacuum-potted,  | Same      | Vacuum  |
| .  Rugged: |               | reinforced      |           |         |
|            |               | epoxy.          |           |         |
+------------+---------------+-----------------+-----------+---------+
| 5.         | Empty         | Sili            | Same      | Vacuum  |
|   Low-cost |               | ca/epoxy/hollow |           |         |
|            |               | ball composite. |           |         |
|    filler: |               |                 |           |         |
+------------+---------------+-----------------+-----------+---------+
| 6.         | S             | Epoxy-sealed    | Same      | Flange  |
|  Leak-free | pring-loaded, | welds.          |           |         |
|     ends:  | teflon        |                 |           |         |
|            | lift-plate.   |                 |           |         |
+------------+---------------+-----------------+-----------+---------+
| 7.  Small  | Pr            | Epoxy-sealed    | Same      | None    |
|     stored | essure-relief | hollow balls.   |           |         |
|            | valves.       |                 |           |         |
|    energy: |               | Thin-wall pres. |           |         |
|            |               | relief.         |           |         |
+------------+---------------+-----------------+-----------+---------+

LHe Displacer Solutions:

+---------------+--------------+-------------------+------------------+
| **Sta         | **Hollow     | **Hollow Sphere** | **Vacuum         |
| cked-Cylinder | Sphere**     |                   | -Insert**        |
| Vacuum Logs** |              | **Filled-Insert** |                  |
|               | **F          |                   |                  |
|               | illed-Logs** |                   |                  |
+---------------+--------------+-------------------+------------------+

Warm Diagnostic Wiring Requirements:

+------+-------+---------+----------+---------+---------------------+
| **Si | *     | **Wires | **       | **D     | **Remarks**         |
| gnal | *Bund | (1)**   | Source** | estn.** |                     |
| Ty   | les** |         |          |         | **(4,5,6,7,8,9)**   |
| pe** |       | **(#/bu | *        |         |                     |
|      | **    | ndle)** | *(2,3)** |         |                     |
|      | (#)** |         |          |         |                     |
+------+-------+---------+----------+---------+---------------------+
| High | 10    | 10      | Low      | SHV-out | Twisted within      |
|      |       |         | er/small | panel   | bundles.            |
| V    |       | H.V.    | V-tap    |         |                     |
| olts |       | Teflon  | box      | (SV35)  | E.S shielded.       |
|      |       |         |          |         |                     |
|      |       |         |          |         | 1 KV                |
|      |       |         |          |         | (bundle-bundle).    |
+------+-------+---------+----------+---------+---------------------+
| He   | 2     | 10      | Upp      | Heater  | !6 Ga: (2 twisted   |
| ater |       |         | er/large | patc    | pair).              |
|      |       | 4-16    | diag.    | h-panel |                     |
|      |       | Ga.     | box      |         | Twist with twisted  |
|      |       |         |          | (SV-60) | 10-wire.            |
|      |       |         |          |         |                     |
|      |       |         |          |         | E-S shielded.       |
+------+-------+---------+----------+---------+---------------------+
| Low  | 6     | 32      | Upp      | Ctrl-Rm | 16 twisted pair.    |
|      |       |         | er/large |         |                     |
| V    |       |         | diag.    | (S03,   | E.S shielded.       |
| olts |       |         | box      | S04)    |                     |
+------+-------+---------+----------+---------+---------------------+

1.  Sensor wire size: 24-28 Ga. (to keep things small and flexible (for
    easy shielding and assembly).

2.  Cryostat ends: female connector that safely mates to the cryostat's
    male (continuous shield).

3.  Protect cryostat connection: against water, dirt, and bumping.

4.  Bundles: Twist as tight as practical within bundles. Twist bundles
    lightly within E.S shield.

5.  H.V. Bundles: Protect adequately for 2 KV between bundles, and any
    bundle to E.S. shield.

6.  E.S. shield: Cryostat end should be flexible for two feet or more.

7.  Heater- Supply wires: 2-twisted pairs/bundle (16 Ga or larger).

8.  Heater Bundle: Bundle by twisting the twisted 2-pair with the
    twisted 10-wire.

9.  Electrostatic shields: Flexible at the cryostat; continuous to
    destination.

Signal Transport Specifications:

+-----------------------------+----------------------------------------+
| **Requirements**            | **Implementation**                     |
+-----------------------------+----------------------------------------+
| 1.  Sex convention:         | Signal source = male; power source =   |
|                             | female.                                |
|                             |                                        |
|                             | Amplifier output is male only.         |
+-----------------------------+----------------------------------------+
| 2.  Hypertronics            | Left to right facing the source (M/J17 |
|     block/column numbering  | at bottom).                            |
|     convention:             |                                        |
|                             | Pin 17 reserved for shield.            |
+-----------------------------+----------------------------------------+
| 3.  Diagnostic wiring       | Excitation currents before voltages.   |
|     convention:             |                                        |
|                             | Signal before reference; Plus before   |
|                             | minus.                                 |
|                             |                                        |
|                             | Excitation pins are 1(+) & 2(-) + 4\*N |
|                             | (N=0,1,2..).                           |
+-----------------------------+----------------------------------------+
| 4.  32-pin amp.breakout:    | Add new channels as LEMO cable         |
|                             | water-falls.                           |
+-----------------------------+----------------------------------------+
| 5.  Signal "OR-ing"         | Distribute locally processed signals   |
|     minimization:           | (like Imag, Imbal, Ref) thru a local   |
|                             | breakout panel.                        |
+-----------------------------+----------------------------------------+
| 6.  4-Pin/2-pin diagnostic  | No changes or additions needed.        |
|     flexibility:            |                                        |
+-----------------------------+----------------------------------------+
| 7.  Patching cables (6ft):  | 70 2-pin/Lemo                          |
|                             |                                        |
|                             | 25 2-pin/2-pin Amphenol.               |
|                             |                                        |
|                             | 25 Lemo/Lemo.                          |
|                             |                                        |
|                             | 10 Lemo/BNC (single, reference gnded). |
|                             |                                        |
|                             | 10 Lemo/BNC (dual/differrential).      |
+-----------------------------+----------------------------------------+
| 8.  Patching boxes:         | Add three Lemos to every available     |
|                             | box.                                   |
|                             |                                        |
|                             | Make & label one as inverting.         |
|                             |                                        |
|                             | Label owner and provide secure         |
|                             | repository.                            |
+-----------------------------+----------------------------------------+
| 9.  Lemo wiring convention: | Lecroy: sig. = bulkhd male, ref. =     |
|                             | bulkhd female.                         |
|                             |                                        |
|                             | Reference color = black                |
+-----------------------------+----------------------------------------+

Magnet Transport/Restraint Requirements:

+----------------------------------+-----------------------------------+
| **Requirements**                 | **Implementation**                |
+----------------------------------+-----------------------------------+
| 1.  Axial displacement (low      | Eight, 6" iron wheels on roller   |
|     friction):                   | bearings.                         |
+----------------------------------+-----------------------------------+
| 2.  Tranverse displacement (low  | Multi-tons (borrowed).            |
|     friction):                   |                                   |
+----------------------------------+-----------------------------------+
| 3.  Height & vertical angle      | "Out-rigger" jacks on cart        |
|     adjustment:                  | corners.                          |
+----------------------------------+-----------------------------------+
| 4.  Axial insertion (low         | Cam-follower "roller-skis".       |
|     friction):                   |                                   |
+----------------------------------+-----------------------------------+
| 5.  Capable of bridging any      | Roller-skis are 48 inches (1st to |
|     insertion gaps:              | last roller).                     |
+----------------------------------+-----------------------------------+
| 6.  Roller peak-pressure         | Crowned roller-wheels (30")       |
|     reduction:                   |                                   |
|                                  | Spring mounted skis..             |
+----------------------------------+-----------------------------------+
| 7.  Cart/cryo transition roller  | Double roller density at middle   |
|     safety:                      | of each ski.                      |
+----------------------------------+-----------------------------------+
| 8.  Parallel skis:               | Adjusted when mounted.            |
+----------------------------------+-----------------------------------+
| 9.  Seismic constraints:         | Welded/slotted barrier bar-stops. |
+----------------------------------+-----------------------------------+
| 10. Cryo/vac sealing-flange      | Teflon bumpers on cart's          |
|     protection:                  | rail-extension.                   |
+----------------------------------+-----------------------------------+
| 11. Insertion/removal systemt:   | Insertion screws;eye-bolt with    |
|                                  | come-along.                       |
+----------------------------------+-----------------------------------+